It is an interesting point to be explored in terms of global aging trend.
I consider what you mentioned and observed has nothing to do with the country you are living in, instead, it is more correlated to the age of referred people. In general, the older you are getting, the less flexible you might probably become no matter what country you are observing. I would rather say people would be liable to judge a person by one's previous experience and knowledge learned as they were young.
It is said people with higher education are apt to live more happily and flexible to the changing of the environment which often suggests they are less stereotyped, whereas there is no strong evidence to identy the theory so far.
Interesting observation, this is very very true and i know the exact reasons why it works this way.
It's due to in different cultures there are different roles for different people and genders. So in many cultures adults are given more power or influence you can say, whereas younger ones are given lesser power. So it sort of balance that up. For example in South Asian cultures or subcontinental cultures ( India, Pakistan, Bangladesh and Nepal and Sri Lanka ) adults are very powerful and sometimes it goes to very extremes, they decide your marriage partners and they even decide what you study and so on. Whereas young ones are supposed to obey the adults even when they're wrong for as in respect. However, as cultures are involving, this trend is slowly and steadily dying now. I hope this is helpful and if you want to know more you can ask.