The only thing that really matters in role-play is whether or not someone is able to pull off a compelling, interesting character that fits the setting and doesn't rely on numerous gimmicks. To be blunt, some people just aren't cut out for role-play and it shows with how they present their characters. It's the same with pretty much every other activity out there - I'm terrible with technology but I'm pretty good at sports, acting and role-play.
If people can't figure out for themselves that it probably isn't a good idea to have their character conjure a meteor to kill someone else's character without their consent then I don't feel as though I'd lose out by choosing to ignore them entirely - especially since I don't have much in the way of time or patience for people who can't work out that you need to play fair and compromise when indulging in a group activity with other people.
If people can't figure out for themselves that it probably isn't a good idea to have their character conjure a meteor to kill someone else's character without their consent then I don't feel as though I'd lose out by choosing to ignore them entirely - especially since I don't have much in the way of time or patience for people who can't work out that you need to play fair and compromise when indulging in a group activity with other people.