It's the fatal conceit of soi-disant Secular Humanists: they don't just say "God is Dead", they go a step further and elevate humanity (i.e. themselves) into that role. So they get to, literally, decide things like who lives and who dies.
These types rarely have the stomach for it themselves, as it's dirty and too much like work. So they always enlist a corps of thuggish enforcers to do it for them, which I guess also puts in just enough degrees of separation to allay whatever latent fragments of morality remain in their brain stems. Maher tries to pass his off as that of an irreverent, curmudgeonly critic and satirist, but this is not just shock comedy. As IDP notes, there are people who honestly would be cheerleaders for offing the "right" people. One day they'll find out they themselves have become the "right" people.