Some of them can be useful...like maybe what kind of multimeter people have. The age one I found interesting. And the joke one about resistors had some funny answers.
Polls are there just to know what u think about the authurs question on the topic he created. Some r just for fun, some are to know what u think n what u like.
So I think that there must be polls. But many of it is also not good at the same time.