He's the defensive midfielder for the team that has just won the Champions League, I don't think he's overrated at all. And even if he is, it's moot because he's still way better, and more effective than Veron.
Re the CL, that's partly why he's overrated. Being part of a CL winning team doesn't mean you're a great footballer. Take Nicky Butt for example.
Can't agree that it's a mute point, given that Mascherano is a far better defensive midfielder and Veron is easily better at distributing the ball and creating chances than Cambiasso. Maybe you could argue that he should at least be in the squad, but then it depends on how Maradona wants Argentina to play. Cambiasso in the past few years isn't the same one that was part of the Argentina 2006 team imo, he sits back too much nowadays with mediocre movement and looks awkward whenever Inter are in possession. That's just based on what I've seen, which admittedly isn't a great deal outside of CL and a few big Serie A games, but I can see why Maradona doesn't fancy him at all.