Umm ... Kurtz is pretty right, here. He's saying that part of the reason conservatives don't come into mainstream media like they do is because they don't apply for it ... they'd rather stay at the big conservative publications.
To a certain extent, he's right. Several conservatives (I'm thinking specifically of Ann Coulter) are trying to tell young conservative journalists to avoid working at National Review or the Weekly Standard and instead apply for jobs at the NY Times or Wash Post.
He misses the point that there's a clear absence of conservative voices in part because of the established liberal domination of the newsroom, but his idea that conservatives are purposefully staying away has some merit.
It's got to be pretty miserable for a conservative to work in a hostile atmosphere like the NYT or WP, can you blame them?