That's true enough. Whilst I'd have been upset to see Pete and MJ divorce, if it had been written well (so not by Quesada, natch), I probably would have been OK with it eventually. Certainly when Pete and MJ split up a couple of times prior to OMD and even when she was 'killed off', I never dropped the book. Only One More Day made me do that.
The problem with OMD (for me, anyway) isn't about the moral implications of the whole 'deal with the Devil thing', but it's the unfinishedness of it all. It's a hanging thread, a loose button... I mean, it created an entirely false reality and swept twenty years of continuity under the carpet (and no, OMIT resolved none of that, no more so than Marvel's repeated insistence that "everything happened the same, just without the marriage").
At the end of the day, a Pete falling out of love with MJ would have been hard to accept, but ultimately it still would have been Peter. Yeah, it would have been a Peter not written especially in character. But it would still be Peter, nonetheless. OMD, however, created an alternate Pete - a parallel version that was (and remains to this day) a completely different character as far as I'm concerned. Even now, ten years on, the idea of reading about him still feels like reading what is essentially an Elseworlds story.