That was a pointless wall of text when all you could have said was "QQ, some people are newbs and others have different views than me"
Not everyone wants to kill every mob in the instance, myself included. I like to mix quest xp with dungeons, and I find that it is faster to get XP via doing dungeons once for the quest xp/mob xp and then going back to quests. If you don't like doing that, OK, that is fine, it's your preference, just be respectful of other people's preference.
Also, not everyone's been playing the game since beta, many people in the low level dungeons are new players who don't know what the hell they're doing.
The best way to deal with these people is by running with friends/guildies and avoiding them all together. Aside from that, suck it up and take it. It's LFR, not a Paragon raid.