Please don't take it as criticism when that's *exactly* what it is? And you clearly don't think it's a sterling job because of the intensity of your reaction here.
The problem is, if SMF were to stop and implement this now, it'll be another 2-3 years before 2.1 comes out which screws it up for everyone. It's already been too long getting here. This should not be considered for 2.1 - but maybe for 2.2.
That also said, the mentality of SMF has always been about people *talking to each other* with pictures being attached to a message, not the core of the message. 2.1 does improve this, you can now put attachments into the body of the message with little effort, but the reality is that the core priority of SMF has always been - and should always be - people writing messages for each other. Everything else should, and must, by definition be secondary.
I'm not saying it can't be improved, but it must be done carefully - and we must remember not to build for the minority. One of the open source organisations I work with has exactly this problem; they've just geared up having spent most of the last 6 months on a new feature that, as far as I can tell, only one of their customers is going to use and that it flat out doesn't work for any of their other customers without code changes which, frankly, their customers are not in a position to make anyway.
The majority of forums are not visual or heavy on attachments - we have sufficient evidence to support that position. The vast majority are text based, exchanging conversation - that absolutely must be the priority. Would that change if the features were better? Maybe, but unlikely.
Also, what does 'one click uploading' even mean? I literally do not understand how to do one click uploading in ANY platform. Every single platform I can think of requires a flat minimum of 2-3 clicks to do anything (yes, that includes Facebook). As for resizing, I'd strongly make that configurable rather than the default, there are plenty of times when I've uploaded large images with the intention of them NOT being resized and been frustrated when platforms do resize them, but those are cases you don't run into like sharing large structure diagrams of systems that have hundreds of tables. Just saying - if we support your use case, we have to support mine too as mine is just as important to me as yours is to you.