I turn off the chat, and do my own thing. If someone wants to contact me, they'll whisper and I can honestly say I have only gotten positive whispers in LFR on most of my toons. Either about a mogg, my dps or someone asking me about tacts since I've been the guide. I did get some insulting whispers on my paladin since I wasn't topping healing meters (the top one had 550 ilvl, mine had 517) and I simply replied "/yawn" and ignored him. Since I was still pulling a good amount of weight there was no chance he'd get me kicked.
Life is easier if you don't spend every awaken moment worrying about everyone else. I've had bad experiences in LFR, yes, but would I quit over them? Hell no, there's plenty of stuff to do and Flex = a good thing if one doesn't want to do LFR. It requires more of you as individual though, but still.
Durumu was a nightmare to a lot of people, but I actually enjoyed it on LFR when it was new...why? Because usually I together with a small amount of other dps and 2 healers and a tank who knew the tacts would carry the rest of the group after the first maze, making the others members of the group grateful and giving them a chance to go past Durumu.