It is true. Not only do you have to train physically at a whole different level in the NFL but with the Giants, you have to master a very complicated read and react route running package. Manningham, despite his enormous gifts, never got it completely. Jernigan and Randle are still struggling to get that part of it. Not much different from RB who better not fumble and darn well better protect the QB. If a WR is making the wrong reads, he will sit on this team. It doesn't mean they won't get it and it doesn't even mean they are not working hard. It just means that they aren't grasping the essentials of route running to play for us.
Never argue with an idiot. They will drag you down to their level and beat you with experience!