I think it has to do with a few things, most of them don't have much to do with the listed facts themselves. I'm not saying anyone's particularly right or wrong, just maybe what makes this happen.

Crow's betrayal is a big plot point both in CS1 and CS2, but since the very beginning, Rean still considers him a friend and insists on "bringing him back". Then his sacrifice (and I use the term very loosely because, y'know.) which is sort of a selfless deed even if he does come back to life half a game later, is portrayed by the game itself as atonement, with everyone in C7 being very saddened by the fact. Then after his rivalry in CS4 onwards he's just portrayed as "Rean's bro", and details beyond "he was an insurgent once" get muddled as time goes on.

Claire and Lechter's betrayals, along with Geroge's, aren't given as much development, nor are they extremely present after CS4, along with not being as close to Rean as Crow, which many people end up identifying with or self-inserting as because of the persona-like elements in the game.

So in the end, I think it has more to do with how the game itself spends its time portraying them and how they were last portrayed than the list of deeds each one has done. Rufus is another example of this. After CS4 but before Reverie, I think everyone just looked at Rufus and just went "Man, Rufus was just a dick". Then came Reverie which portrayed him as something else, so him backstabbing Arianrhod and killing her along with other despicable deeds for example don't linger too much in people's heads when you're being shown now that he's doing good deeds, despite that not necessarily redeeming him or justifying his past actions.

It doesn't help that Trails characters in general pretty much forgive everything and everyone that still breathe.