Well, they could always have different colors, or maybe a symbol or something. And also say exactly what it means when you hover over it. I don't know, I just don't like the labels being on thread topics, it makes it seem like they're different just because of having a poll. I know for one, I've made many threads over the years that didn't need polls, but I just put them there for the sake of it, but I'd never like people to go into those threads expecting the poll to be the "main" thing. If we have to keep the text labels, maybe they could be in a different place, like in the bottom line of text or something?
Edit: as for threads with the label sticking out, I'm not sure about that. Maybe it does for most people, but for me personally, at first I was inclined to actually avoid those threads, because they felt a little... alien. So it's not necessarily something that attracts more attention.