I'll say this. In general, polls are against the community guidelines. However, these player run polls were allowed to operate and run their course repeatedly over the multi-month beta process. Certainly someone felt they were generating some kind of useful feedback or they would not have been allowed to continue.
I think it had more to do with the feared backlash at closing the poll threads that were clearly critical of the new class system rather than them getting useful feedback. After all, they told us the system was here to stay. Period. And the off-spec penalty was here to stay. Period. Not much wiggle room for feedback that by and large said either start over or it needs a massive overhaul.