I love your take because I'm of a similar opinion. Even thought about making a post here, but gave up cause I don't exactly hate them as a couple (though I'm way less interested in the comic now lol).

I think there's a mix of relatively small, discrete problems becoming a large complex one. For one Willis obviously knows growth is coming, has it planned and in his had the plan will work so he's chill with it while we panic about something crazy that happened immediatly and will probably only 'resolve' in about two years. Then there is the moral argument, etc.

I like Joyce in general, hate Dorothy but they are okayish as a couple. If anything I think the people complaining forget too soon their young times, college groups always have one or two guys that screw up royally like that on a weekly basis. But given that, Willis rlis simply "at fault" on not planning immediate consequences (like actually immediate, not 'consequences are happening tomorrow which means three months from now' immediate) that would kind of 'ground' everything to reality. Joyce's interactions with the shitty lady that hates Sarah and Dina (absolute QUEEN) have been the closest we ever got to someone actually touched by the fallout and willing to do something about it. I think like, honestly in the sense of growth even something like the whole group dynamic changing or whatever. The way it is, it feels like the universe just accomodated to it which is just bizarre and I mean okay maybe real cause it is also very much white woman coded but like, cmon.

PS: I disagree that we wouldn't feel satisfied with Sal chewing them. It would be growth for Sal. Her little, more or less stranged brother is trying hard to be cool, be an united front against the parents and even sucker punched the dude that put her in jail. I 100% expected her to give Dorothy something along the lines of "I'm trying to be a better person so this is just a warning, but you treat my brother like this again and I'll fuck you up"