Interesting points, Jeep. I think what many say on this site and others about the "non-broken" ones who just want out, there is a reason. And the reason is a shiddy relationship that we contribute to and that's apparently fixable if we can get them to stay and listen (via DBing or whatever).
I think MLC would fall into the broken category, though. And the permanent issues of past abuse, psychological/emotional/neurological issues are also in that category. So maybe it's not an issue of temporary or permanent but broken and not broken.
Again many sites advocate for us to stop seeing our partners as the faulty ones and look at our own culpabilities. The issue is when we do this and the other person is really in fact seriously damaged, then what do we do? The crutch may be believing that they'll change if we change.