Hopping on the "Niji not that bad guys I swear????" bandwagon, as much as I wish Millie could thicken up her skin (seeing as she's the one who hosted the anon chat stream), you can absolutely see and understand her and Luca's frustration in being known as the black company Vtubers. Things like "black company" or "Riku yacht" feel like they obfuscate legitimate concerns and criticism to have towards the company.
Do they dox anyone who leaves? No. Do they hire minors before going "hey guys this person is a minor, PLEASE don't make porn of them that would be REALLY bad oh no"? Absolutely not. Are they still probably one of the best options if you're looking for a corpo? Yeah, especially if you're a male Vtuber.
Do they lack transparency? Yeah. Do a lot of their choices feel questionable, aimed at appealing to shareholders, and focused on short-term? Definitely. Does Riku currently give off the impression of a spineless coward hiding in his office to occasionally give his shareholders the safest bullshit answers imaginable? A hundred percent.
Niji's just in the negative spotlight right now due to a mix of these issues and consistent drama. They're pretty much in the situation Hololive found itself in in the past, constantly being in issues and being considered the strict no-fun idol company in comparison to Niji letting people like Noraneko or Mito do whatever they want. Whether they can get out of it over time remains to be seen.
As far as listening to Matara and Kuro over Millie, as some people have already stated, do keep in mind that they also have reason to prop up why Vshojo is a hundred percent a super good squeaky clean perfect company. Are we forgetting Kson's talent freedom meme? Kuro-wise, I also wouldn't exactly trust someone who tried to cook the books and couldn't even do that right. It's pretty much a matter of he said she said at that point.