Late back to the thread, but some excellent posts from innocent and Jeanne. seriously makes the very good point that there is a wide range of 'good enough', i.e. not dysfunctional, parenting. And yes, in those cases there will be niggles and mistakes, and it's important to remember that those parents were only human and not dwell on the fact they weren't perfect.
Abusive and dysfunctional parenting is a completely different matter, and needs to be recognised and thought through in order that it doesn't repeat itself in the next generations.
The OP has pressed a few buttons because the Larkin poem says something that many abusive parents tell their own children, should they dare to rebel: that they'll be just as bad. My own mother told me that whatever she did to me, I'd do to my own children; also that I'd pass on a 'generation of hate'. It was a weapon to hit out at me because I was standing up to her. It's so awful for her to look honestly at what she did that she has to believe Larkin's sentiment is true.
Incidentally, there was a poem written in response to Larkin by Adrian Mitchell, called 'This be the Worst':
They tuck you up, your mum and Dad
They read you Peter Rabbit, too
They give you all the treats you had
And add some extra, just for you
They were tucked up when they were small
(Pink perfume, blue tobacco-smoke)
By those whose kiss healed any fall
Whose laughter doubled any joke
Man hands on happiness to man
It deepens like a coastal shelf
So love your parents all you can
And have some cheerful kids yourself.