They prove that people like voting. And that they like giving their opinion. And that those opinions mean something to them. And that some people don't like some other peoples opinions. And that opinions are like Lemon curry. It's really good, but if you eat too much, you get sick.
Even though it's a humour thread, I gave a serious answer: No. I see that 'Yes' is currently leading, which means most people are given humorous answers, which makes sense.
Well, it proves that those people who come to EN World and vote in polls like voting in polls. Or at least feel motivated to vote in polls for some reason.
They prove, without a doubt, that the person posting the poll has too much time and interest in a topic that ultimately means nothing* as an Internet poll.
*Though Internet polls have other uses, such as random curiosity/fun. But, as said, they are still basically meaningless in a scientific proof sort of way.