Disabling the Polling option would have the same effect on comments as disabling smilies.
Most people are able to express their complaints just fine without resorting to graphics. Polls in support forums tend to become similar to questions like, "When did you stop beating your wife?". They start with a pre-defined assumption.
It helps everyone to stick to problems, complaints, or questions.
And no I don't work for WebAssist, just a volunteer.
10 Tips for getting quick help from a support forum