Why Angolan basketball players can't break in NBA!

Name:Joaquim Gomes(Kikas)
Team:Primeiro da agosto
FIBA MVP: 2008 and 2009

Joaquim Gomes has played in professionally in Germany and the Netherlands and currently plays for Clube Desportivo Primeiro de Agosto in Angola. Moreover, at Valparaiso University in Indiana, United States, where he played from 2000-04. He had a career-high 23 points in the final of the Mid-Continent Conference tournament in the Crusaders' 75-70 win over IUPUI on March 9, 2004.In 2005 he won the German basketball cup with RheinEnergie Koln.
However, after spending about four years in America he still not able to get a contrac to play in NBA. He won FIBA Africa MVP(most value player) in last two Africa championship.
It's still a mesterious because if look at last 9 years of MVP award winner of african champioship are all angolans then why none of them manage to play in NBA. How they could be MVPs in African championship where included some of players who actually playing in NBA but no Angolan ever played in NBA.

Year MVP Award Winner

1999 Mali Lamine Diawara Lamine .
2001 Angola Miguel Lutonda Miguel.
2003 Angola Miguel Lutonda Miguel.
2005 Angola Olimpio Cipriano Olimpio.
2007 Angola Joaquim Gomes(Kikas).
2009 Angola Joaquim Gomes (Kikas).