They're worse, because they choose to be worse instead of better. They COULD just stream and be vtubers and be fucking normal about it while obviously still having their quirks about them, but they willingly choose to indulge in drama, cliques and general trashy behavior and humor. Both the guys and the girls are bottom of the barrel garbage content that you can already get from streamers that make their money by trying to be trashy and controversial on purpose. They're the same shit which is why their quality of character is lower and why they're perceived as such.
As far as I know, the company lets them do whatever. And by having that freedom, most of them choose to behave like trashy children, so they get treated as, and are perceived, as such. That doesn't necessarily mean Hololive talents are better, it just means Hololive talents choose to not be as shit as Nijis.
>tl;dr fuck niji and fuck their shitty high school gosspi-tier garbage drama they always got going on