That's the thing though, there's an undercurrent of "actually it's responsible adulting to do bad things, sweaty" to it. They have thought terminating defense mechanisms that respond to exposure to uncompromising ethical positions on things they have proudly compromised on with rage. Fascists worshipped the suffering and death that their actions brought to everyone including their own ranks. Far right liberals believe that brutal subjugation and abuse is "responsible leadership," believing it to be bad but necessary. Mainstream liberals tie their brains in knots to ignore the suffering capitalism and the brutal violence it requires causes, finding justifications for inaction. Radlibs reflexively move towards the mainstream and concede and capitulate to it, and have been trained to be enraged by anyone who does not.

It's material conditions. They can absolutely know, on some level, that our politics are more morally correct (what I guess you mean by "better") but also know, on some level that their politics benefit themselves personally more. They're siding with the politics that personally benefit them, and getting angry at the ones that are more correct but would mean they don't continue to benefit from exploitation of others if implemented. Then there are other people who might even themselves benefit more if all exploitation were ended but have bought into the arguments made by those further up the ladder.