Having read all your responses I am now going to question myself to see whether I have the same opinions.
There may be some truth in me having a bit of a self esteem problem with not having a career. I'm just thinking about whether this was my deeper motivation for starting this thread, although I don't think it was.
I didn't love my job, only moderately liked it. It wasn't a 'dead end, unskilled' job but wasn't a high status career either. I was good at it before I had children, but then with children on my mind, and tiredness from childcare, and the fact that I was only then doing the job 2 days a week instead of full time like before, so not so 'practised', I became less good at it I think (although my boss says not). Being less good at it than before was having an effect on self esteem.
Although I left the job because the tiredness from doing that and childcare was making me a bad tempered mother and I felt it was having a bad effect on the children (so I should have had some feeling of satisfaction that I was doing the right thing) I also felt like a failure. I failed to manage to be a good mother and work part time and I wished I had been 'strong' enough to do both.
I admire people who do both.
There is a lot of truth in the 'accusation' that I don't have enough self confidence to 'prove' myself in a demanding career. Self confidence was always a problem but I was gradually working on it and doing gradually more demanding jobs. When I got 'worse' at my job after having children it set my self confidence in this area back and I think I have less faith in myself now to be capable of going back to a career. It is true that the thought of it frightens me.
So maybe there is some resentment there that women who have good careers and children are better than me.
Having said all this, it didn't feel like any of that was on my mind when I wrote the OP. I felt angry when I read someone on another thread say that they worked most of the time and dreaded the time they spent with their child. I felt that even if people don't realise how hard it is being a parent until they do it, they should not then 'give up' almost, and try to 'get out of' doing it. The child didn't ask to be born, the parents made it happen, so they then need to put lots of effort into doing a good job of looking after him/her, even if it is hard.
I've found myself agreeing with articles written by Oliver James recently. The reason I feel so strongly about it is because I have past issues to do with neglect. So does he. Maybe then, I should question whether this means I feel oversensitive about it. (And whether he does too.) I don't feel that both parents working full time is as neglectful as some things that I experienced as a child. Maybe I am reacting too extremely to anything that looks anything like neglect.
I have an issue with two women and one man in my life who neglected to do what they should have done for their child because of their own selfish reasons and weaknesses but maybe I am translating this to ALL parents, especially women, when the negative feelings about it should be more confined to those specific people.
Just the fact of both parents working full time maybe a lot less bad than I think, if they aren't doing it because they can't stand to be around their children who they find to be an irritation. If they are giving them all the input (not materially, but emotional input and time and interest) that I felt I didn't get, as well as working, then maybe it isn't as bad as I think. It must be very hard work to do all that though and people who manage it must be almost superhuman. Is it really possible?
If I refine what my 'issue' is, I think it is with parents who don't like being with their children, find them just an irritation, and have had them just because they feel they should 'do a bit of everything' in life or because it is 'the done thing' or the 'respectable' thing but they don't really want to do the work of looking after them. I probably shouldn't assume that the situation of both parents working full time always equals this. Maybe most people in the world are not as rubbish as the specific people I am angry with.