mock those younger than them now.
See this article:
https://writingandrhetoric.cah.ucf.edu/wp-content/uploads/sites/17/2019/10/KWS2_Kitt.pdf
The greatest generation was described as wanting the world handed to them on a silver platter. They were mocked for rejecting traditional dancing and music and adopting "modern" entertainment. They were seen as sexually immoral.
Every generation rejects the values of the one before it, even if the new generation goes to WWII. They were still kids and still had a value set that didn't make sense to the generation before them.