I know that looking at Faye's behavior from the outside, it make perfect "logical" sense to say "why does everyone put up with her?" and act as if she's a horrible person. I also know that even in real life it sometimes makes sense to cut someone out of your life when your interactions with them are only enabling their self-destructive (and destructive to others) behavior, or when their behavior is only hurting you; sometimes you have to distance yourself from something toxic for everyone's good.
But I think it's easy to forget that Marten, Dora, Hanners, etc are Faye's friends. Friends accept. It doesn't mean they overlook problems like this, or ignore them. But it also means they don't just say: "You're in a bad place, you're a terrible person, this is hard for me to deal with, so good luck on your own." They say: "How can we help you," even if that help is of the "tough" variety (and that can even include, at the most extreme, distancing themselves. )
Faye's not evil, she has a disease, and right now she isn't even willing to admit to needing to get well. That's a hard place, and while I wouldn't condemn anyone for wanting to get away from that (being a friend/family member of an addict can be hell, and no one should be guilted into feeling that its their responsibility to fix someone else's problems) I think we're forgetting what the running theme of this comic always has been. If Dora's response is immediately hardcore, and new-confident-Marten might be closer to that than we'd expect, and Hanners might show that hidden (but always present) backbone, I still couldn't see them ever stopping being Faye's friend, nor trying (in whatever way is appropriate) to help her move beyond this.