Like every poll also Jazz polls are no independent judgements nor do they represent an
objective view of music or musicians - especially when the poll is the result of sold records/CD's.
On the other hand: If you look at a poll from your individual view you hardly would agree to it totally.
But what are polls for then?
They reflect the change of taste and the change of music over the time - so the comparrison of years and decades gives some helpful information about the development of music.
The most known and most reliable poll in Jazz is the Downbeat Critics Poll - Jazz critics vote on different categories every year. Started in 1953 this poll is something like a constant in Jazz history.
Here I've compiled all the results from 50 years as a compressed overview! Since the categories have changed over the time the poll is splitted into four parts.
50 years of the Downbeat Critics Poll