Most likely you're right... but Dirk wasn't a hall of fame even by the 5th year of his career.
There's tonnes of #1 picks who had really good NBA Basketball careers who never became Hall of famers and some still playing who probably won't either (Derrick Coleman, Larry Johnson, Chris Webber(not a lock) , Allen Iverson (not a lock), Kenyon Martin, Yao Ming, Elton Brand... I can go on.... )
but needless to say, not every person that steps into the NBA is a superstar... sometimes they're just your average All-Stars (Vince Carter, Chris Bosh, Billups, Shaun Marion, Antoine Walker. yada yada) ... not the Elites. (I.E. Magic, Bird, Jordan, Kobe, Wilt Chamberlain, Lebron, early Shaq, & Wade )
I do think Barnani... is better than a bunch of recent #1's Bigs at least... (Kwame Brone, Andrew Bogut, Yao Ming and Greg Oden.. think how Portland & Houston must feel.... at least Andrea, is capable of playing in more than 10 games a season.)