Not big sweeping complaints, but just little things that other players do that annoy you?
When I’m playing disc priest and there’s always that one ranged DPS that stands out of range of my PW: Radiance and I have to run over to apply Atonement to them so they don’t die.
My favorite is when it’s a hunter and they go “oh no I’m taking damage” and reactively use Disengage and force me to run even further out to get them while they’re DPSing while moving and I’m sweating trying to keep them up 
Players that don’t say thank you. Who’s raising these barbarians?
People trying to share my fishing pool.
It’s not a huge peeve, but it’s really the only thing that I can come up with.
People are afraid to communicate in trade & general.
Pugs that don’t respond to “hiya.” Antisocials get the preemptive boot.
Also people who get mad or bully other people that say “meowdy”
No meowdy haters allowed
The only thing that even mildly bothers me is when someone asks a question, I am the only person to answer them, and cannot get a simple “Thank you”. I feel like common courtesy is just a thing of the past anymore. I even thank randoms who drop in and help kill elites if I am in a jam.
The fearmongering and ban threats I discovered in low level keys. Good grief, players, it’s a game. Yet some (not all) will insta-rage if something doesn’t go perfectly in a +3. Mind blown with the overreactions.
I have yet to see the same mentality in +11 and up. So far have not.
Someone keeps taking my favorite loitering spot in Dornogal.
The reason people don’t communicate is because they are afraid to get reported.
And you just proved my point.
Fearmongering.
I take it back , I had a rogue named Whiskeyslim or something , thank me for getting his game unstuck. He was the exception to the rule, most players on forum , never say thank you.
Frankly I think parking Longboi between the bank and AH in dornagol is hilarious. It is just beautifully arrogant to show you " don’t need any of this city crap anymore"
makes me giggle when i see it.
There aren’t enough of them. I wish this game would spend its time and energy attracting more players than extracting more money from the existing ones.
For example in BGB people wont even post strats or ask for help because of what I posted before. This isn’t fearmongering just truth.
There is a Holy Paladin who posts videos of Solo Shuffle on YT, and when someone in his opinion plays bad he literally reports them.
Lol that is not true at all
I don’t mind if you fall asleep during a run but I hate it when they snore.
It is, on my main account I play Rated, Solo Shuffle, and Arena people wont communicate. Just because you don’t see it or it doesn’t happen to you doesn’t mean it doesn’t happen.
He’s reporting for playing poorly and showcasing it, that is quite the outlier. So report his butt if he truly is abusing the system that way. I don’t run pvp much. But he has all the needed info supposedly displayed on YouTube. Should be straight forward. Youtube personalities are not godmode.
I have never played with or against him, on YT I watch a lot of PvP videos and his was suggested.
Point is 10-15 years ago chat on BGS or PvP was alive and well, today nobody will dare post on chat for fear of being reported.
For example on my main account 80% of the time I play with friends and communicate on discord, as a matter of fact I have combat chat disabled.
But they’re not communicating because they’re afraid of getting reported, there’s just not that much downtime in this game anymore to type stuff in chat. It’s why you mostly see if people do say anything it’s at the start of a match, dungeon, etc.
In older iterations of this game there was a lot more downtime like drinking, wanding, running out of mana and auto attacking, etc, and a lot more opportunity to chat with people. Go play Classic and see for yourself.
No one is afraid of being reported unless they just can’t stop themselves from saying something bigoted or are aggressive 100% of the time. And those people get rightfully banned and then learn to stay quiet. But everyone else who can be a normal adult isn’t afraid to talk to each other, they just don’t have time to.