I wonder why the low critics' rating?

There was a push at the time by left-leaning sites to dislike Joker. Long before it came out, they decried it as incel propaganda and wrote it off. When it came out, it got standing ovations and rave reviews, and I think that might have rankled critics who had already committed (or partly committed) to an anti-Joker stance.

Ironically, as you point out, the film is more complicated in its real world political applicability. Joker seems as much antifa as he does incel and the film uses a gross and arrogant Thomas Wayne to question the values of our hero (Batman) and the worldview he represents (Batman is about a rich guy punching poor people and using expensive toys to do it).

Of course, I'm sure many of the critics were just viewing the film fairly and thinking that it didn't have substance to back up its veneer of comic book politicking. I liked the movie myself, but I can understand where a critic would think it shallow; everybody gets their own opinion.

And that's what a critique of a film is, at the end of the day: one person's opinion. They might be well-versed in cinema or more articulate on paper (might be, anyway...in theory...) but it's still just one person.

probably because it's not very good

It is a derivative film.

Its not that good really. It did hit a nerve i guess. In a world saturated by instagram and superficiality Joker gave a lot of shallow people a chance to feel deep, I guess? Great acting from Phoenix though. And the camera is pristine. But I find the movie to be extremely derivative. A poor mans king of comedy with a hint of Taxi Driver.

no, poor people just need to stop overpopulating the earth

I believe it has, what, a 72% on RT? I’d say a 7.2/10 is the perfect score for this movie. It’s fine, but it doesn’t really push the envelope nor is it groundbreaking on any level.