I understand that I made a pretty broad statement, but anecdotally, there are so many different instances of boomers denigrating choices of later generations across many different buckets of choices - social, technological, moral, cultural, political, psycho-sexual; and as I've lived my life, we've seen rapid chances in societal behaviors that just make me feel that as every successive generation comes into existence, you just get that bit-flip for that dimension of the 'collective consciousness' (not woo-woo collective consciousness, but just the aggregated set of behaviors and interactions manifested by the people that exist today, that came to pass based on the pre-existing cc from their parents and those that influenced them, etc).
Psychologically, it's funny, because there is this commonly cited concept of 'teenage/adolescent rebellion' where, despite the love and adoration you feel for your parents, there develops a kind of rift in response to the rules imposed vs. what you immediately want to do/desire to explore the world without the parental control structure that was imposed previously. Perhaps the generational shifts that are seen are a consequence of this - maybe not, I'm just thinking out loud here. But yeah it is an interesting topic.
Care to comment further on what gave you this impression? I'm intrigued.