Copious amounts of privilege (read: no skin in the game), and exposure to nuance without having the critical thinking abilities to maintain perspective both locally and historically.
Hence, idiocy like: 'Lets defund the police but also, someone broke into my car last week and I went to the police station to report it.' Or any sort of rage about colonialism/patriarchy, etc.
A solution would be to force many of these people to live in, say, Managua or Nouakchott for a short period of time, before returning them to the recesses of Palo Alto or Northern Virginia.
Exactly this and it's frankly hypocrisy.
From my experience, it feels like a lot of them try to gain a sense of superiority through the social justice lens without critically thinking about the real problems or even working with the people they claim to be supporting.
White liberals is a huge category though, and I think these are just a small but quite vocal minority. People of just about any ideology are always going to have small levels of hypocrisy and holes, I think ideally the best people are those who are willing to listen, learn, and grow to form nuanced positions on a variety of issues, reguardless of how far "left" or "right" those positions may be.