I love Tony Parker, but defenders still go under picks on him as well. Also, if you think that Tony Parker plays harder on every play--particularly on the defensive end--than Rondo, I dare say that you haven't watched him play all that much.
I'm a Boston born celts fan who has been in the San Antonio/Austin area since 1979 so "I dare say" I know a little about this subject.
Yes, players choose to go under the screen on Tony, but it is not because they do not respect his shot anymore, it's because Tony's drive is killer, and he goes in with the intent to score or get to the line. For years, Tony has had one of the top FG% at the rim (including big men). That is what Rondo is missing. His shot is already improving, so add that next element, and Rondo can be better than Tony.
And yes, Tony does play much harder than Rondo, even in "meaningless: games...hands down. Pop would rip him a new one if he didn't.
Over the past 5-6 years Parker averages about 65% at the rim, Rondo's at 62%. Not much of a difference. There isn't much of a difference in their long jumpers either. Parker's probably better at it but that's something fairly recent in his career. When Tony was Rondo's age he was a pretty poor jump shooter, to the point where his uncontested jumpers would regularly clang off the side of the rim or even hit the backboard when he didn't appear to be aiming for it.