@ Zekk: Smurfs aren't the most Codex adherent Chapter in existence, there are others that follow it more closely, but they are just the Legion of its creator and GW's poster boys.
Sorry if that sounds a bit narky, I just wanted to point it out.
I suppose you have a point, but that's just one of the big contradictions of the 40k universe: psykers = warp, warp = chaos, chaos = evil and damnation, yet Emperor = psyker etc.
There are many different possible views on psykers, and all have lors of evidence to back them up. Personally, I think the no-psykers image fits the hard-line image of the Castigators very well, and the following rules for the rules-sake of painting armour blue, maintaining old records in writing etc is very evocative of the Gothic, crumbling systems that make up the image.
Plus it would take loads of effort to change a major part of the Chapter's background, so meh.
