They should also stop leaving the group listed and auto queue active when a group is half full or more and boss is already pulled and nearly dead, and especially in an invasion point. And when a world boss/world quest rare/invasion point is finished if you're the group lead disband the group immediately do not leave it listed.
Seriously people join these things to make those activities go faster, waiting for a spawn timer because everyone has this mentality to join the largest group instead of the freshest usually results in waiting for no reason, and not to mention whether you care or not it actually makes half the group lag out when you have a bunch of people from different servers/regions loading in at the same time.
TL;DR while I am SURE that trolls do this stuff on purpose, the bottom line is it makes things take more time not less, where the point for a lot of us who are skilled/geared to the teeth and know exactly what we are doing is to get through the content FAST. What especially needs to stop is people who linger in group after they downed the shit, it's far too often that there are only 2-3 groups up for a world boss at a time and all of them are those lingering groups where the boss was already killed, and the raid lead left and it auto passed to someone who joined late and just kept the thing listed.
Again, just to make sure you understand this makes YOU and the people who are just trying to kill the thing fast take much longer than they have to. If you stop doing this kind of behavior the result will be more people making groups, and MORE groups is what makes this go FASTER not huge groups but only 2-3.
For Argus World Bosses I understand wanting a larger group so the wait time isn't a big problem (and almost never happens anyways) but for old content it's not necessary, as a few people (if they're decently geared) can kill the Broken Isle's/Broken Shore bosses in under a minute.
And as far as things like for invasion points go, half the group is literally doing nothing anyways because they don't have to. So stop helping to make the game more toxic, because instant rewards for doing nothing is exactly why the game is so toxic.
I really do not understand why people have this mentality that the larger the group the better, but in a world where we're constantly pugging most of the game's content following these easy tips on group finder etiquette will help a lot in ways you wouldn't even realize.
Just for example, back in the day it was very rare that someone would rage pull or try to rush people to pull when they might just not be ready, and get pissed off for literally having to wait a few more seconds, this is actually a thing that happens extremely frequently in the game now? Why? Because those kind of people will find another group in no time at all, or otherwise get rewarded for being tools and not contributing anything positive to groups they join.
It's up to the people making groups to make sure that these kinds of things don't happen.
On a related note, man I hope tanking in BFA is like 20 times harder than it is now because it would be AWESOME if I didn't have some shithead that has a tank spec just for the even faster queues etc taunt a boss like Pit Lord Vilemus late or on top of me when I have the debuff, and then talk mad shit because I died 100% due to their ineptitude and complete lack of understand of what the tanking role is even about/what the bosses mechanics even do.
Seriously guys if we gotta use this group finder to do most of the content in this game, please use it responsibly, there's a lot of bads, and mouthy kiddos out there that need to be kept in check.