Unlike other topics, polls, either here or elsewhere, have two parts that keep them running: post content and the poll itself. Most people tend to make the poll last forever the most often, so people can still use the poll if people have had their way with it interest-wise. And then sometime down the road someone notices an existing poll of interest without a newer topic for it and sees that they can use the poll because that is still active.
To me, if you make the poll active until deletion then I think it's fair enough to say that people can post their response to what they chose instead of making a whole new topic. I mean, why not use what's already around? And why deny them a post since using the poll would be pointless if no one knew about it? XD Typically, I tend to make each of my polls last twenty-eight days. At which point the poll ends and then it's just a matter of interest dying and posts ceasing.
So all that I can say, is if you think old polls are unsightly and you don't want to see them, then start defining how long your polls last. ;p Then I'll "crack down" on reviving dead posts if the polls are dead. At this point I'll consider these posts (with active polls forever until deletion) the undead, zombie topics. Be nice to the zombies. XD
So, what do you think? I'm all up for suggestions and hearing you out and stuff. Just keep in mind that I'm approaching this through technicality and functionality, not by a notion of what's "not right" or "unsightly." Reason with me, don't peer-pressure me. ;p But by all means express what you like, how you like.