The reason the community went down hill is not due to LFG/LFR/CRZ, the reason the community went down hill is because threads like this would rather argue about the problem then work to fix it. Join a dungeon, talk with people during it, you will find some may actually answer you and enjoy the conversation. Now and then you will gain dickbags that don't, that is like, just like how sometimes I bump into a polite individual on the sidewalk and other times a guy that slams a door in my face as I walk up. Introverting myself and blaming the "system" or the "community" does not fix anything, being polite and letting the dickbags roll off me DOES.
You can't even use "But I will never see them again!" as an excuse, because CRZ and BattleTags exist. You like that healer you just grouped with, click his portrait and invite him to be friends. You can group again.
I will say it one more time. We need to be the ones to fix the community. The issue is we have to many people complaining about the problem, only to log in later, join a LFG, never say a word, and then blame the other four people as anti-social dickbags rather then realizing you never said anything either.