All condescending arguments aside,
I can promise all of you that these are not concoctions of my imagination. It's happening right in front of me. So many times it just doesn't look like Rondo is interested in shutting his man down on the defensive end. Jameer Nelson sure had his way on the offensive end for those last few games against Orlando... Am I saying Rajon isn't a good or even great player? No. All I am saying is he's not as much as a lock-down defender as he is lead on to be. That's my opinion. It's not "nonsense" and it's not "whining."
I guess I lied. I did kind of address condescending comments with the last sentence...
Sure, Nelson had a good game or two, when Rondo was having back/leg spasms. In general he didn't get a lot done though. And you're right that Rondo isn't a lock-down defender. What you're missing, though, is that since they changed the hand-check rules, *nobody* locks down point guards. It's virtually impossible to keep someone as quick as a pg in front of you when you can't touch him and he uses picks to get by you.
If you think that Rondo does it so poorly, you should have no trouble listing quite a few point guards that are significantly better at it than Rondo.
It's also worth pointing out that Rondo causes a lot of havoc for opposing offenses. This is important to our team defense beyond the job he does on opposing point guards.