User blog comment:SniperGhost/Gulliman's Return/@comment-25033299-20111021154923/@comment-1932673-20111021183405

Chaos can corrupt anything, and look at the normal timeline, theres tons of prep work that Chaos did to corrupt the legions which you wouldn't know about unless you specifically looked at it, so theres enougth complexity and space to do it. And I think things would be far too one sided if Chaos didn't have any primarchs at all and the Imp has 17. That means that you have significantly reduced the role of the most defining faction of 40k and therefore have lost a lot of crucial character from the storyline.