Do you click "NEED" on everything that drops in LFR even if you already own the item or if its useless?
p.s I do just to cover repairs. I also "Need" to trade / sell to others on my realm and make huge profits. I run as a tank and often run with a druid tank in my guild so i automatically win the tanking kit anyway.
Also i have to say i don't mind when i loose to people doing the same as me. Why? well because the LFR loot is useless to everyone really when you think about it.
If your a guild that just runs normal mode then your going to upgrade you kit fast anyway the LFR stuff is useless.
If your a heroic progressing guild again your going to replace it fast anyway.
If your a guild that just runs LFR then the loot is pointless as you can do LFR in blues if you wanted.
The only point in LFR loot is quick tier sets and trinkets that will soon be replaced or kit for transmogrify in the future.
So i really don't see why people QQ so much if they loose to others.. Just stop it and click Need like most people do in LFR and don't get burnt if you loose as the loots pointless anyway just grind your VP and get better kit.
Here is an add-on that will automatically "Need" on everything you can need on and "greed" on everything you cant need on.
http://www.curse.com/addons/wow/autoconfirmloot