There are multiple types of people “hating” Manjaro to various degrees.
There are the “It GoEs AgAinsT ThE ArCh PhiLoSopHy” guys - those you should ignore without a second thought. Because duh, that’s why it’s its own distro and not Arch. They probably also hate Endeavor, Garuda and all the other great Arch based distros and have no idea what they are talking about.
There are the ones who, like myself, tried Manjaro briefly, realized there was something broken right out of the box, thought “lol stable my ass” and then invested way too much time in Arch on another distro. You should ignore us as well.
There are the ones who at least claim to have proberly used Manjaro for a while and say there is no noticeable benefit, if not disadvantages. They might have a point (shout out the the guy or gal who mentioned their frequent certificate fails lmao).
And finally there are those who have decided Manjaro just isn’t for them and moved on. They can probably give an actually balanced and fair review of Manjaro.
But then again, there are also people maintaining and liking the project, so there seems to be at the very least some perceived value to it. Maybe it’s worth it, maybe it isn’t. Frankly, I don’t care whether people this distro. And why should I?
I also don’t get why a couple dozen DEs exist, when I hate everything but Plasma and Cinnamon, maybe GNOME. But if people want to use them and go as far as to maintain them, there is probably a reason and I have better things to do than stop them.