It's also kind of stupid. As in, very tiny amounts the things that the "joke" tries to attack are based in reality. Its as if they cannot accept that large numbers of progressive or liberal minded people exist.
I think it's actually the reverse. Your critique is that the NPC meme ignores that lots of liberals/progressives exist.
The rightist promoters of the NPC meme would agree with that statement -- but they would say that it's because most are just acting as ideologically/memetically programmed automatons. Crucial to understanding this meme is that its promoters see "libs" not as literal bots, but as humans-with-bot-thinking, who have grown up on a diet of platitudes and mantras without deep analysis.
On the contrary, the left/libs/progressives (whatever you want to call them) on Twitter have had a habit of actually doing what you're saying, when they pull out the "oh look another Russian bot" troll. That meme actually asserts that the number of actual conservatives/right-wingers is literally small and being amplified by actual programmed chatbots.