Is it really because of performance? age? competition? that's why no team from 82 teams aren't showing interest for this guy?
I don't want to think of other reason aside from his poor performance because we can't justified that, Yao Ming is an Asian and he played many seasons in the NBA, I hope this is just all about business and nothing more personal like discrimination.
There are many talents in the NBA and mostly Americans, so I guess those agents from different teams will give priority to their own talents than those foreign ones. If you are a foreigner and you will not exceed other talented american players then expect nothing less than being a junk in that league. Afterall it all comes down to business.
It depends if you have a skill like the legendary Ginobili and Parker but if you played like most of the average local players then you're out. the most recognizable thing about those unique players is their hard work and willing to improve themselves. if they don't meet these criteria then they cannot expect to be hired by the NBA TEAMS.