In many ways, Maher is correct. I've been speaking about human nature in these forums for years, and although I consider myself a classic sort of liberal, I do not try to pretend that we can make humans give up their biases. I do not pretend that we don't, each in our way way, try to satisfy our own needs to the best of our ability -- and that we sometimes do so at the expense of others. We are not programmed like social insects -- or the Borg -- so that our own self-interest doesn't exist -- it does, and informs much that we do.
I'm not far left, although I am definitely on the left side of the line (maybe 3 out of 10 lefty), and I'm certainly not an idealogue. I hate "cancel culture," and have strongly objected to removing statues and renaming schools and the like simply because we can't accept that our ancestors lived in their own culture, and can't be expected to reflect the attitudes of ours, which they couldn't even have contemplated.
I also know that we can't change other people. I'm gay, and I'm always going to be gay. You can make it illegal, or you can shun me for it, but it's not going to change who I am. We have to admit that although we'd like to give everybody the chance to attain a PhD, not everybody has the ability to get there, or even to a lower-level college or university degree. And yet, that's no reason not to help them, if we can, reach for the best they're able to achieve.
Maher was, of course, perfectly correct about the biggest problem with communism -- you simply can't get people to stop wanting not only what their neighbour has, but even (God Forbid!) to outshine their neighbour -- don't keep up with the Joneses, go them one better!
But this is a problem on both sides, not just left. The right really does think that you can create a society in which everybody marries the girl next door and has 2 1/2 kids and a couple of pets, go to church every Sunday and never, ever cheat on their spouse. Well, too bad, you can't, and for trying to do so by force, they deserve the dunce cap. And the left really does think you can make everyone "equal" by fiat -- that a person born physically male who "identifies" as female is certainly going to have developed characteristics, due to nothing more nefarious than the hormones their genes decided they produce more of, that make it unfair for them to compete against a person born with physically female who produces different hormones.
To that last point, which is a matter in much contention these days, I think we have to acknowledge that, with the best will in the world, we simply cannot fix everything, and that while we can make some allowances, it must surely be wrong to make allowances that permit others to be unfairly out-advantaged.
Yes, that's something we all need -- both left and right: to humility to know that we can't make everything right, and that we have no right to make demands of other people that they cannot fulfill.