If bone spurs - or various other health issues - are inappropriate grounds for draft deferments, perhaps the rules at the time shouldn't have allowed them. The fact is a lot of guys escaped the draft for a variety of reasons, including hanging around in college for years and years. Others had such a high lottery number, there was no chance they'd be drafted. They could have enlisted, but they didn't.
I don't know whether I have less respect for fellows who legally "dodged" the draft or for those like McCain and Kerry, who used less-than-honorable military careers as a springboard to a lifetime of suckling at the government teat and stuffing their own pockets.
In any event, McCain probably should deal with the beam in his own eye.