I couldn't agree more. Even if 2 WR's are running in a zone by a defender, and the defender is covering one of them, because he can change directions so quickly he can easily cover both even if they are running in opposite directions on a crossing route at full speed. In a true zone defense, each defender usually can only cover one person in his zone and someone from another zone has to move over to help out. This is easily seen when a defender is covering someone 10 yards down the field in his zone and you throw to a RB coming out of the backfield at the line of scrimage and the defender magically changes directions and gets to the running back before the ball gets to him.
I am finding that very few routes are working this year because defenders can cover such huge areas in zone and they never play man coverage. Out routes are too risky, crossing routes only work some of the time, corner routes are worthless. The routes that seem to work best for me are WR drags and in routes, quick slants, post routes, fly routes, and passes to the RB for short yards. But this severely limits the plays I call and makes it much less fun to throw. I've been practicing and getting used to this years version after playing 05, and I hope this will help but I just hate not being able to run simple routes like out routes and never have any success.
Also, this isn't just a problem when I play offense. When I play a cover 2 or 3 zone the computer rarely ever has any success and it makes defense too easy. Hopefully sliders will help.