I don't think it's as prevalent now, it has become adulterated over the years as the classes have mingled. It still exists though, many middleclass parents are still fairly detached from their children and they have learnt the detachment from their own parents. My sisters and I were able to see how friends we made were treated differently. We had attended a private school but when my mother lost a son and my father realised that she could not have any more children we were taken out and sent to state schools in Tunbridge Wells, which although very middle class still had a mixture of children attending its grammar schools. It was a real eye opener. As for our own grandparents - I had one lovely grandmother who was I suppose lower middle class. She was petrified of putting a foot wrong socially. I loved her dearly. The other one taught me to walk with a book on my head and made me sit and eat with a book on my head. I went to stay with her when my mother was ill, a few times. She criticised my lovely grandmother, said that it was common of my mother to have had four children and that she was no better than a brood mare, got her hairdresser to chop all my hair off in that awful style that children had in the 30s, threw all my clothes out and bought me new ones that I hated (definitely no trousers) and constantly criticised our manners at every opportunity. Luckily, being a 'distant' grandmother, we didn't have to see her all that often. Worst of all, she gave us a father who had no idea whatsoever how to show affection. She sent her children off to school as fast as she could so that she could have a social life. My aunt said that she often refused to have them home in the holidays, and of course they were at separate schools so didn't even have each other.
Ex's mother was a revelation. She was a wonderful mix of all the lovely grans on here. Offered to babysit without being asked, bought useful little gifts, was thoughtful and genuinely interested, very caring and I so wish she had been my mother. MiL is also like that but more absent. So what can I say? It is my own experience of the class difference. I used to think it was because of having to live in smaller houses, that people had to learn to understand each other and get on and were better people as a result. Naïve I know, but our house was huge and sometimes we didn't see each other all week apart from at Sunday lunch when we were all growing up.