The reason that I 'change my argument' is so that I can try to find some way to make it relatable since at every turn you've thrown back strawman arguments, though I doubt you realise they are strawmen.
The thing that kills me, though, is that you're actually becoming me at a faster rate than I hoped for. Don't be like me.
Breakdown of logical fallacies:
* slippery slope: if we adopt x, why shouldn't we also adopt y, z, a? Especially not what was suggested, let alone on the table. Though I do know use of Symfony was discussed for 3.0 some time ago. As pointed out, SMF is a framework in its own right because the definition of framework is very nebulous at this point. Sure, you can have SMF without a framework, it just won't do anything.
* slippery slope: barrier to entry. The assertion that it will lower quality of work. Maybe it will. Maybe it won't. People will always find ways to do stupid things. But you know what is worse than a platform that enables people to do things? A platform no-one cares about because everyone else has made it easier for them to do things.
* ad-hominem: attacking me rather than attacking my arguments (I later merely started reflecting what I saw)
* slippery slope: layers of abstraction. Yes, as a general rule fewer layers of abstraction make it faster, but the opposite argument stands: if performance is a consideration, maybe
Asm32 should be the platform of choice. Ditto for customisation - after all, there's absolutely no levels of abstraction involved there, you have the power to literally do anything the machine can do. Except this is also a slippery slope in itself, elitist yada yada yada.
* strawman: templating system is not a framework, it is a component, and every argument about using components vs frameworks is targeting the overall framework vs current platform as framework.
Yes, there's a performance consideration, however modern template engines are the product of quite a few years of meta programming at this point and most of the time, they end up compiling to something very similar to what the hand rolled PHP might look like, especially if the time has been taken to simplify the template in the first place. Right now with the templating system work we've done in StoryBB, the templates that are cached run approximately 0.02% slower than the original PHP forms. In reality I've taken a much larger hit in StoryBB with the subaccounts system we have.
Yes, there's a potential quality impact. But looking at what has actually happened out in the real world in the use of these systems, themers and modders haven't made anything worse than they would already have made in PHP, just they had to work harder at it to make PHP.
Yes, there's a possible flexibility issue. Or at least, there is if you're assuming how templating systems work and you're trying to fit SMF's code directly into a templating engine without thinking it through. There are lots of weird things SMF does in its templates that shouldn't be in the templates, and there are things it does that should be in the templates but aren't. This is the result of not abstracting things away in a higher level plan fashion, partially because at the time it was built, abstractions were a luxury that couldn't really be afforded the way they can now. You can make the argument about performance here too, but there are things that exist in the ecosystem now that didn't exist then that largely mitigate that angle too (and out of the box, actually made worse by SMF's behaviour than not, e.g. template eval which not only hurts debugging everywhere, it also rules out any use of the opcode cache)
Yes, I could even be behind the fact that there can be a debugging issue. Is the issue with the template engine or is it with the template? Every time I've asked this question, I've found the problem is not the engine, but me trying to use it incorrectly to do something clever rather than doing it the logical, simpler way. And the times it's been an issue e.g. I've forgotten a brace somewhere, the engine I picked doesn't help me as much as I'd like. But this is a symptom of picking a specific implementation of an engine that isn't as friendly as it could be, not a symptom of the whole problem. It's also one that I haven't seen much in practice across the various ecosystems I haven't seen. And in reality it's a variation on the 'fun' of programming in PHP in templates where I use a comma instead of a period between things because of operator precedence in echo statements (because that's not easy to get into in practice when you're doing inline ternaries), or I mismatch braces.
The 'one syntax for another' argument is interesting. Let me reframe the situation, maybe it'll help you understand my perspective: why does TypeScript exist? what about CoffeeScript? These things literally do nothing that JavaScript can't do (because they compile down to JavaScript), but people like them because they abstract away some of the really annoying things in the underlying language. That's all that's going on here, really.
The kicker though, is that this debate reminds me of me. Everything I see in this debate echoes me, and this isn't a good thing. It makes me begin to question how much of a force I personally have been for good in this environment, and makes me think that my naive idealisms over the years have encouraged others to do the same - and I'm not convinced in some of those positions of argument that I was right. There was certainly a time when I argued against frameworks as a whole, and certainly a time when I argued against template engines, too. I find a lot of the same old issues, though, an over-cautious conservatism at a time when the entire fleet of platforms in the forum space are routinely castigated for failure to innovate, and it's harder to drive innovation on any level when the platform decides it wants a barrier to entry for even modest things like putting something to the screen. It's the same reason we don't use C to build a forum, we like having the abstractions. I'm just arguing for one more abstraction because it feels like it benefits everyone.
The key things I was trying to address, and I appear to have confused people in trying to explain:
* people who are admins who want to do simple customisations of their own - these people aren't programmers, they just want to insert the bit of JavaScript for Google Analytics by copy and paste like GA tells them to, except surprise, they have to figure out quoting syntax. Or the people who just want to tweak a little bit like the header. They're then dealing with what amounts to mostly HTML and CSS, as opposed to PHP, actual HTML and CSS - and all evidence suggests that people find this easier to do simple changes. There's a reason people like the theme stuff in XenForo and IPB - it lets them make little changes without any hassle. They feel empowered, they feel like they can own something even though they're not technical. Not every SMF admin is a programmer or a designer.
* people who are theme people get to play with something closer to what they normally use rather than stepping through hoops. Yes, it means people can do stupid things more easily - but at the same time, it lets people who know the tools do so without having to remember to escape quotes. And people will always do stupid things, this shouldn't be a barrier to making tools easier for non-stupid use cases.
* when I build Moodle plugins, even though I'm not even required to use the template system because Moodle doesn't mandate it (because Moodle doesn't use it itself for most of its plugins for historical reasons), most clients are requesting it so they can have a designer customise it without knowing Moodle's code innards. And Moodle certainly has PHP 'templates' in its core in the renderer system. Though that's a level of mind-killer with its many classes and layers of abstraction that I wouldn't impose upon anyone. But I digress - designers are the people who would like this.
Also, on an ironic note, this debate somehow ended up talking about C. Who remembers the doomed project smflib, that reimplemented bits of SMF as C so they would be PHP extensions for the really really big forums? I do...
