There are at least 3 types of LFR players;
1. The kind that do LFR every week to maximise their gear performance, maximise valor, reforge, gem and enchant. They learn the strats either through research or experience. This includes casuals who don't have time to schedule raiding and those who raid but want extra shots at tier tokens, trinkets, ect. They bring food, they bring flasks. They want to perform well. They enjoy LFR when it runs smoothly.
2. The people who only play long enough to reach max level and then gear up enough to see that Tier's boss drop in LFR. Once they have this achieved they leave the game until the time when the next expansion is about to drop. Then they get about gearing up again but they only do the bare minimum. They dont remember their rotation, they don't gem or enchant or reforge. They show up in SoO in half 463 blues instead of spending an hour getting 496 tokens. They dont care about learning strats, they just put down Garrosh and leave until the next expac is near.
3. The people who go afk, people who go afk because others go afk and those who think they are too good to deal with trash or too good to do anything but afk. They would rather spend an extra half hour wiping the group than actually playing the game. They blow repair bills because its more fun to shit in the pool than it is to swim in the pool for them. The real loosers go afk and try to use it as an escuse why others should not be able to be in LFR.
Just like people who shit in public pools they ruin it for everyone, and then they say, "Well if others can shit in the pool then I should be able to too, you shouldn't be able to shit in the pool but as long as you can shit in the pool then I will continue to shit in the pool." and then they go bitch out the manager of the pool that someone shit in the pool, "This is your fault for having a pool that someone can shit in in the first place! Having my own pool that no one but my friends could access made me feel special until you opened up this public pool and anyone can shit in this pool! I was in the pool when I took a shit in it and this pool should be shut down for health reasons!"