It was also a matter of drafting very bad receivers who couldn't learn any offense in the NFL.
Givens, Branch, Mitchell, Jakobi Meyers managed to handle it just fine.
I can't think of a single young receiver we drafted who failed at it then went elsewhere and succeeded in another offense.
The same goes for vets that refused to pick it up or couldn't like Galloway or Ocho, but that was maybe an old-dog-new-tricks situation.
Yet Welker, Amendola, Hogan, Brandon Lloyd, LaFell, Moss, Stallworth, heck even Jabar Gaffney handled it just fine.
This really seems to be a talent issue versus a knowledge issue.