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.