A lot of times I either mean to make a new poll but forget to click on "New Poll" instead of "New Topic". Also I sometimes decide that I should make a poll after I've already started the topic. I know you can just go out of the new topic screen and click "New Poll" or just post the message and then add a poll (if you have the right to-you might not). I think it would just be easier to put in a "Add Poll link in the regular new topic page.