It isn't about shaming or punishing those who ghost on games. But, as a matter of protecting ourselves and the success and enjoyment of future games it is worth looking into the history of players and GMs to see whether they've ghosted before. There are a number of people on here who start up a new game every couple months before abandoning it and starting another. If that's fine with you, then great. Play with them and enjoy the next two months for all its worth, just know what you're getting into. I'm not interested in investing my time and energy into a game or player when I know that at any moment that person may disappear with no notice.
I'm no stranger to the guilt/death spiral. I routinely go weeks between IC posts (and feel really guilty about it!), but I always check in OOC. I don't think I'm somehow better or less broken than others on here. If people give notice and are upfront about delays and issues they are having then yea, I'd be happy to play with them again. But like Roughtrade said in his post about interviewing the GM, how they treat players in the application process is relevant information for deciding whether to join their game, so is how they communicate their availability in past games.
Anyhow, to avoid going in circles, one point of The Myth-Weavers GM Talent Pool (which has a grand total of two GMs participating so far...) is to provide coverage for GMs needing a mental health break. Don't leave for 3 weeks and feel super guilty about it, get a sub! Let someone else keep the momentum going so you can return refreshed instead of slinking off feeling awful about yourself.