Generally those people will be dickheads about it though, which makes the main reason for them getting kicked not doing a lot of DPS but being a dickhead about it. Or applying it to the wrong target (Horridon anyone!).
That said, it feels to me like there is more to the story than the OP is telling us. I've (since DS) never seen anyone get kicked without (good) reason from LFR. However, it might be due to a technical error of sorts.. Although this would be the first time for me to hear about an error like that.
There's something missing here, you're fulled gemmed/enchanted (prouda you, not many LFR raiders takes the time to fix that) and according to the description you shared with us, you're not doing anything wrong, keeping it to yourself, playing well etc.
Unless you forgot to mention anything, I can't really help you out here.