We can shit on libs all we want, but we can't run from the fact that we need to convince millions of them to see things our way if we want a snowball's chance in hell at getting anything significant done.

We need to get the "mass" part of a mass movement from somewhere. So where are we getting the bulk of people we'll need to seize state power (by whatever means you prefer) if we're writing off all the libs from the jump? Keep in mind that Bernie leaned hard into activating people who aren't ordinarily political, and while that had some success it wasn't close to enough by itself.