What up ASA- Honestly most people who are that tall are very slow and don't move well which is a very big part of the game.
There have been guys in the past and right now with Yao in the NBA and Yao is one of the few who has been succesful because of how coordinated he is for his size- but others have not been as coordinated and didn't really enjoy very succesful careers- Gheorge Muresan, Manute Bol, Chuck Nevitt, Shawn Bradley, etc.
Nickster