To that end, they just publish what they see

I mean, I am not a defender of PFF player evaluations, but they are as qualified as any fan to "use their eyes". They just have a format to publish it. What if their eyes are on things you don't see? How was, say, Buffalo's right tackle last year? I don't know, do you?

So, people can know that someone did watch and grade the film, week-in and week-out.