Well, what did you expect, really? It was only logical and right thing for the Grey Knights to do

I would have loved to see Dark Angels successor chapters like my favourite Guardians of the Covenant.
I would have enjoyed playing Minotaurs too

But I understand that having too many chapters and sub-chapters is actually a bad thing

Let alone having too many factions

so they have problems with GreyKnights? GreyKnights are psykers as well. No problems with inquisiton?

As far as I know they don't know about the Grey Knights in the first place.

The Grey Knights are pretty much the only ones they don't have a problem with.

They would get ass-raped if they had

Well i wouldn't want to go against the grey knights even if i was a black templar

I thought the only two chapters who knew about the Grey Knights were Blood Angels and Space Wolves?

and dark angels and black templars--gw is very inconsistent in their fluff.

Full chapters? I don't mean the chapter master or a select few. I mean the entire chapter. I know Space Wolves were granted knowledge and one of my knowledgeable 40k friends said Blood Angels also got to know. I've never heard about Dark Angels or Black Templars knowing.

You know what's funny now? Re-reading the new Space Marine codex, it doesn't say anywhere that Black Templars hate psykers (though they still don't have Librarians), they hate "the witch" which is any non-Imperium psyker. They love their astropaths and Navagators and have no disgust fighting along side Chapters or armies that have any sanctioned psyker. Heck technically there's no rule that says they can't have Librarians, just a little blurb that says they lack them.