I agree completely about Purify not getting the ball enough or even being on the field enough for that matter. The rumor that I have heard is that he doesn't know the playbook that well. To me this shouldn't matter, he should be on the field until he is tired, we should run whatever plays he does know, it's not like our playcalling has been that varied anyway.
I would say that Purify is our best player but he isn't being used nearly enough.
If you look at other teams that have good receivers, they are on the field almost always.
It is not a mystery when we are running, Erickson is on the field everytime, I'm sure the other teams have noticed this by now, it's been this way for several years.