Its hardly a "claim"... Kurt Warner's main flaw as a QB was that he tended to hold the ball for a long ass time. Who doesn't know that? Football Jesus played with what, maybe six current or soon-to-be hall of famers on offense in his best seasons? Pppht... right player, right time. He had great touch on the ball, but the way he held the ball back there, which often bordered on that fine line between bravery and stupidity, there were a lot of teams that wouldn't have let him on the field. His style only worked with hall of famers to throw to and to protect his blind side.
And given that the 2004 Giants were going nowhere - and man, if you watched them play that season, whatever the record was, you had to know that they were not at that point a playoff caliber team - I had absolutely no problem sitting Warner down and getting the kid some experience. Watching Warner get sacked and throw dump off passes was doing absolutely nothing for me.