I can see his point to an extent. The private chat channels DO lesson the mixing of people from different cliques. Some may think that is a good thing, but remeber you do/did not actually know anyone that you run with on a regular basis, you met them in game, by runnig with people you didnt know. If you stop running wih people you do not know, then you stop gain new friends. Eventually everyone leave games, so eventually your friends will leave and you to will leave because you know nobody else and no longer hae fun.
As bad a name pugging gets, it is what lead to getting to know the friends you have now. What he is saying, I believe, is chat channels stifles this, which is bad for new people and ultimately bad for the game.
As for Raiding, many guilds, including Sabbat, has had a huge influx of players come back to the game and the need to pug out the last few spots is not needed now. We have a very healthy raiding schedule, you just do not see the LFMs because there are none.