I am amazed by the illiteracy on this board. Half the responses in the thread clearly didnt read the OP
30 is "old" for most of the players that came out of the draft at 18 and played heavy minutes at an early age without proper training. Add that to the fact that these NBA players are mostly all over 6'6"... and if you know anyone who is NOT an NBA player over 6'4" who is older than 25 they almost always have knee, back, or some joint issues. Thats just the way it is. Brett Favre you can make an argument for but he only plays 15 - 20 games a year and has skipped full contact training camp the past few years and doesnt go full contact ever in practice. Its not worth it for a GM to invest millions in a player who could potentially need surgeries that take them out of the lineup for half the season, if not more if there are signs of joint issues. (ala T-Mac) If players like T-Mac want to still get signed with another team they have to prove they can still handle the wear and tear by playing through injuries like Kobe did last year.
So that's why I've been depressed for years! And all this time I thought it was the countless injuries the Rockets have been dealing with, seemingly forever. Thanks for straightening me out. (seriously, nice thread idea!)