This is something that I deal with a lot. For the sake of clarity, I primarily play the following games:
- League of Legends (stopped playing after S4 ended)
- World of Warcraft
- Payday 2 (stopped playing ~6 months ago)
- Destiny
- Various other MMOs (RIFT, Swtor, etc...)
Throughout my experience with these games, I have found that there will always be people like this. Yes they are annoying, and yes I sometimes want to throw my computer through the wall before dealing with these people for another minute. So how do I still have my computer?
You want to surround yourself with good people
That's the bottom line, and this is a very simple thing to do. You don't like bad eggs, so why be around bad eggs? If you find some good people to play with, then keep playing with those good people.
Socialize with people and be a good sport. Try to get on the personal level of a conversation, such as a common sports team or region. Bonus points if you can get the other person to willingly discuss something about themselves. I find that the more personal of a level you get with someone, the more likely they'll like you. If you can, make every single person you come across a "bro".
Most important of all though is that you want to do this consistently with any person, both good and bad. You can't blame someone for their bad behavior if you don't make any effort to help them grow out of it. Maybe all that person needs is a friend, or maybe they have never attempted a Payday 2 mission as stealth. I find that many people are willing to improve more if they feel that there is some importance with helping or impressing their teammates. This is in contrast with the "screw it I'm just going to mess around until they kick me" attitude that people can go into when they feel overwhelmed or flustered.
Finally, you want to get these people back in the next game. If you make new friends who have a good attitude and are good at your game, then why not invite them back then next time you're on? As a group, you hold much more weight against potential trolls and the like. That means more support for you and less support for the baddie. It gives someone more incentive to "play nice"; after-all there's more weight to being accepted by a group, and less going for them by playing out against the group.
Last but not least, don't feed the trolls.
I'm serious about this. If someone wants you to feel bad, chances are they're looking for a reaction. Don't give it to them. Again, try to be supportive and help the player to the best that you can. However don't be afraid to set your foot down. If someone cannot, in their full capacity, act as a decent human being, then you're not obligated to deal with it. Remove the problem, find a replacement, and you're set.
In many MMOs, this is easily accomplished via guilds. In WoW and SWTOR, it is common for end-game content to be attempted by guild-only groups. Be a bad sport, and you can be replaced by someone else in the guild or someone interested in joining the guild. While I have seen many bad eggs, it is very easy for a large guild to almost completely eradicate the problem. For example, in my core raiding group in WoW, people will have to have done a non-core raid with us before joining. We can easily deal with a bad egg in our off-time, and this makes sure that our core group only consists of good players.
In other games such as Destiny or Payday 2, it is simply about forming your own groups. Make some friends, and those friends will make some friends. While there isn't any official "guild" or similar system in these games, the same ideals will work. Back when I played Payday 2, I would mess around in random missions to find people who were serious about actually playing the game. I then would invite these people when starting the trickier heists because I know that they are competent enough to help.