I personally think you are overrating Watkins. This is his what, 4th year now? And what really has he accomplished?
Great receivers are great regardless what situation they are in. Hopkins in 2015 had ridiculous numbers from 2nd and 3rd string QBS. AJ Green is great from a mediocre QB.
If Watkins wants 10 targets a game like some of those receivers I mentioned, he has to prove he can produce on a consistent basis.
And while he makes very good plays sometimes, he just is not a great receiver yet and his stats/ apparent game plans from his offensive coordinators (lack of targets/focal point of offence) back that up.