Do you... even play on this server?
Although not to extremes described by OP, the majority of the players I encounter are like that, yeah. They team up unwillingly, if at all, because they want "more experience", even though you can do quests twice as fast while grouped. They act greedy in dungeons, taking stuff which they genuinely have no idea what to do with but they're sure they can make profit from them. Several weeks ago I joined an ICC25 group with a Combat Rogue of mine and I told the group several times that the only thing I needed from the whole raid were the boots from Marrow25. I was the only Combat Rogue in the raid and there were no Feral Druids. We killed the boss, the boots dropped and pretty much every non-caster in the group rolled for them - DKs, warriors, Rets, hunters - you name it. I left after that, saying that I had just one wish from the group for the whole raid and they totally disregarded it and do you know what happened? Got like 5 people whispering me and cursing me, calling me all kinds of things. So in the end they turned it out that I was the bad person because I left the raid. Haven't pugged ever since.
Players mostly look after themselves when completing quests and if you're going to slow them down, then they just leave after they're done. I've had many many cases, the latest one being several days ago, where I went to a quest and had people waiting for the NPC - I ask for invites, I don't get any, then I make a macro to tag the mob immediately and, boy, would you believe just how fast they invite me after I tag the mob... And then there is criticism - people playing an MMO cannot handle any criticism. They either disagree, even though they're wrong, or, after realizing they're wrong, they just say "I don't care". It's like trying to argue with a teenager. A-mazing...
It's just humans. Level up to 80 and find yourself a nice guild to play with. Until then just try to ignore other players. It's for the better. There are good and nice players out there. They're just not that many and you have to find them and stick to them.