Why don't they give top contributor badge in polls and surveys?

For the same reason that Jokes & Riddles lacks a TC badge: it doesn't take a lot of brain power or effort to answer a poll or a survey, which you can clearly see by the type of answers the P&S questions get. Now, you CAN get one in a place like Trivia, but again, that requires some knowledge.

If Yahoo Answers were a workplace, Polls & Surveys would be the water cooler. It's where you take breaks from inane questions, but don't expect to be rewarded for nothing.

Since P&S questions can not have a "correct" answer then there is no way to give a real fact based Best Answer. So, the TC system does not work.

Because most of the P&S questions aren't information or knowledge seeking, and are not looking for help with a problem. Most people who use that category are using more for fun than for help... whether asking or answering.

Because most of the questions there aren't knowledge seeking, and therefore chat violations.

Also, most of the questions there don't have a right or wrong answer, so thay are just opinions and not facts, and best answers tend to be picked randomly.

Polls and surveys isn't a specific category. It could cover a wide range of topics. At least that's what I think.

For the same reason they don't in Jokes and riddles, it wasn't programmed in because the owner of the site, Yahoo, decided it wasn't needed in those two places.

Is that so?

May be, they think P&S is a time-pass section;

It's kind of stupid to me.. I think all categories should give one

you need to dominate the category and p & s is too large a category