When the X-Men found out what Gambit did when he was with the Marauders, they pretty much perma-banned him from their 'group'. He's still allowed on Ulopia and everything, but nobody gives him anything but a cold shoulder at best. What gives the X-Men the right to treat Gambit like this? Emma Frost was once the White Queen of the Hellfire Club, but now they all trust her so much that she's sleeping with the X-Men's leader. Namor has tried to eradicate the 'surface-dwellers' from the Earth more times than I can remember, but they're practically begging him to stay around on Utopia. Wolverine has done more crap in his life than most of the rest of the X-Men combined, but every single one of them would trust him with their lives. Mystique was allowed to be on Rogue's personal squad a while ago, and she's just about the most devious schemer in the X-Men universe. Now they've even allowed FREAKING MAGNETO to chill with them on Utopia. They were very very reluctant, of course, but they still let him into the group. 
What was it about what Gambit did that makes him SOOO much worse than any of the other people I just mentioned??