In my experience, @Elsvieta , this type of bloke tries to tear down his SO because of his own inferiority complex. The thing is, you don't always see it at the time.
In the case of my BF, I realised that I had a problem when I understood that I liked his parents better than I liked him. They were very welcoming to me. I truly think that he'd been mucked up by being sent to a particular private school - his dad was a lovely bloke from a working class background who had managed to get into uni and had taken a science based degree and there was definitely no snobbery around either him or his mother.
I don't know whether this might be the case for the @ForGoldFoxy 's BF, but mine was the product of an all boys' school - one of the 'lesser' private schools in Glasgow. It seemed to have skewed his attitude towards women.
I encountered another former pupil of the same school while I was at uni and he actually brought his fist down on my head when he lost an argument to me in the department common room. I truly believe that he'd have been out of the department if the professor had witnessed it.
So far as my BF was concerned, I look back now and realise that there were several jibes meant to tear me down - comments about my hometown not being as dirty as he'd expected for a coalmining town, a 'joke' about me being 'as pure as the driven slush'... I was also told that he'd avoided introducing me to a friend who wouldn't approve of my ethnic background or the fact that I was studying Russian.
I've just realised how ridiculous the last one was - my BF had taken one year of Russian but was 'advised' to drop it because he wasn't good enough to advance.
Anyway, this is a longwinded way of saying that I agree with you @Elsvieta since I've lived it.