I think that young people is under the same influences that everyone else. Some boys and young men might like the "Andrews Tates" while others might like the freedom to express themselves in more ways than the traditional masculinity and to explore their identity.

Some people say that it is about making it fun or easy. But I think that it is more about what they want. A young boy might know that vegetables are healthy but still want a chocolate cake to the point of getting sick and end up vomiting. Or he might know that it is good to study and get good grades but still prefer to spend the time with videogames. This is similar. Young boys aren't stupid. They do know that for them is "easier" or "more fun" to be sexist. It gives them easy power that they don't have to work for. Sure, on the long term it might mean they get screwed, but they aren't thinking on that. They probably think that by the time they "settle", that being good to that woman would erase the rest of things they have done. Or that by being "nice" to their mothers, sisters and women they value, that is enough. That is why they become angry when a mother, sister or female they consider that they have treated "well" gets angry when they see them being sexist. That is why they use the "it is a joke". They want sactioned ways to be sexist that "doesn't count" for the consecuences. In their heads it is "unfair" that suddently the ways in which sexism was accepted stop being acepted. Look at it this way, sexism allows them to not do domestic chores (which are boring) and have more free time. Also allows them to be able to spend more on fun things and that being considered OK. Of course they don't want to give up on that for something that would offer advantage that are less inmediate.

I think at its core, is the same choice between chocolate cake and healthy food. If you let a boy choose everyday, until he starts having health problems, he would pick the chocolate cake most days. But we also have to give them some credit, because many of them end realizing that feminism also offer them things. They just switch from sexism and feminism to get the most of them because rith now they are allowed to do that. As in "I'm feminist when I'm with my girlfriend but keep the locker room talk with my gaming friends". And it is up to the girlfriend to say "sorry, but that won't do". Then he would need to chose and he would complain about "feminism going too far" but have to accept it anyway in the same way than a boy would be forced to accept that "no more cake".