Did you see how many dropped balls that guy had this year? Aside from one great year, Celek has been average at best. I love the guy, tough as all hell, but drafting a pass catching TE early is not a bad thing.
Celek is a bit of an enigma. He'll have some catches that make you think 'damn I'm glad he's on this team.' Then he'll also drop some relatively easy passes right into the hands of the defense.
He'll go long stretches where he catches everything and then a couple of games with multiple drops.
That being said, Finley would be a MASSIVE downgrade. Finley wouldn't even start on half the teams in this league