I don't think it's overstated. College games do not take the kind of toll a full NBA season does. Sure, Kobe is having an amazing year at 34, but he's the kind of player Jordan was. At 34 MJ was having a very similar kind of year.
A full NBA season is not overstated. Usually players decline very very quickly. But then, MJ played at an all-star level even at age 39. So you can't really compare players like Kobe/MJ since they are special. If injuries (and the chances of getting bad ones increase as you age) don't cause decline then minutes per game certainly will.
Miami Heat: 2011 NBA Finals Losers