HolyGuacamole
"As an adult, I don't like the message that parents staying together for the children gives. It is a bit like saying "look, I am putting up with all of this unhappiness just for you"
Well absolutely. It would take parents with pretty awesome emotional intelligence not to take out their resentment on the kids at some point, a la YanknCock's parents- "My mom used to say they wouldn't fight so much if I did/didn't do X"", or for it not to place an unfair burden of responsibility for the parent's dysfunctional relationship on the kids, like ilovetochat's parents- "i felt guilty that they were both unhappy "for me""
"I think that sometimes "for the children" is actually an excuse not to have to do anything to get out of the marriage. I mean it is hard enough to get the strength to get out of a marriage when there are no children"
Yeah, I've often thought this. Living a lie is less scary than facing a major life change. Sometimes I think pride is involved too. Some people don't want to see like "failures" in their relationships. I don't think that if your relationship breaks down you are a failure, to be clear. I do think it's a failure of courage to live a lie rather than face the truth of a relationship breakdown though.
SGB
"but if your parents were happy as co-parents in an open relationship then that is a good relationship, just a not-particularly-conventional one."
I did think about this, but I think it's a very different situation. It's not emotionally dishonest, for one thing. The parents involved would be affectionate and loving to each other, as well as others outside their relationship. As opposed to a businesslike loveless marriage where the parents either forgo their emotional needs for affection and love, or find it elsewhere.
"what this does teach children is that heteromonogamy is more important than anything else in the world"
I'm bisexual (proper bi, not tittilation for my boyfriend bi) and am not a fan of the heteronormative pressures on society either. I think the "for the kids" families are an example of the damage these anachronistic ideas do.
"Parents who 'stay together' in that they continue to live in the same house but don't consider themselves a couple can give their DC a perfectly good and happy family life as long as the parents have a reasonable amount of fondness and respect for one another as co-parents."
That's not really "staying together for the sake of the kids" though, is it? It's co-parenting. If I understand correctly you are referring to families where both parents have emotionally seperated, possibly divorced etc but are sharing a house to facillitate raising their kids. There's no burden on the ex-couple to pretend they are still a couple, where as with "for the kids" couples there very much is.
hester
The difference is that when getting divorced the parents in the situation are given an opportunity to move on and find new happiness. As you mentioned, some do not seize this opportunity and spend years fighting each other, but most eventually move on, ending the conflict and therefore being better placed to provide an emotionally stable home for their kids. Happy parents make happy kids.