It isn't great no but it's perhaps a better compromise than not seeing a parent at all (my father got a job in the US when I was 12 to escape the awfulness of the divorce and unfaithfulness on both sides). It's better than seeing a parent emotionally abused. It's better than seeing a parent physically abused and it's a darn sight better than living in a sterile home with two people who should never have got married in the first place even though on the surface there were no problems with money, abuse, etc., just two people who couldn't stand the sight of each other in a loveless, fun less environment.
You mentioned OP your guilt at family occasions when your parents weren't civil or blanked each other. Why? Why your guilt. Mine blanked each other at my wedding. I wanted them both there. It was their problem, not mine. My mother was livid that I insisted my father give me away. They refused to be in the same photograph. My father refused to sit at the top table because my mother was there. It didn't ruin my day at all and none of my guests took any notice of them.
Their behaviour is their problem; please don't let it project onto you because it really isn't your fault. I am also sorry that what you saw the other day upset you enough to get you to post and sorry that you have been jumped on. I don't you were intentionally judgy at all. I think that what you saw brought back your own disappointments and pain and you projected these onto the circumstances of others.
It's hard when parents split for what seems no good reason - I remember it only too well and thinking for many many years that they could have just got on with it for my sake. My own children are very much older teenagers now (cripes one is nearly 21!) and I can look back and see it all from a distance and understand more the unhappiness of my parents. I can look at the lives my children have had and think "yep, they've had so much more love and security than I did", whether that makes me and them and my parents people I can look back on now and wonder if it made any of us better people. Probably not, we are all different and each and every one of us has to do our best with what we have.
I am quite quite sure though that the hurts we take with us from unhappy times do us no good allowed to fester and to grow into chips on our shoulders or within our inner psyches. I really hope OP that you find a way to come to terms with your own hurts and to confront your demons because they will do you no good allowed to grow and harm you.
I hope you are OK and that this is the start of a journey to inner healing.
If anyone read that lot well done. If it makes any sense at all I am glad, if I read back to check I'll delete it and not send. If it's utter claptrap please accept my apologies.