Its been 13 years in Marvel time and about 10 for the second gen members. A decent amount of time but not really enough to give up given how often they've been sidetracked for periods. When compressed it would seem like they spend the majority of their time just fighting for survival. Its not a good idea and they wont do it, but If they did and tried to be consistent with logical characterization some of them would view it as running. The only character that's really recently had mission fugue is surprisingly Storm.