Depending on who you ask there might be a different answer, but for me her being a bad actor is a rrat that was born from several circumstances: her personality onstream, the clique speculation, her being one of the most popular female NijiEN livers left and finally antis using her to troll or spread more rrats.
The clique one you probably already know, I don't know how to properly describe the personality one, I'd say hers is more on the cynicial and ironic side, which while it brought a lot of fans it also has it's critics, and finally because of her popularity she is prime target for antis (and one very dedicated schizo)
It is but not for the reasons you think, Enna and Michi/Mika were good friends back when they were both in Niji, so much I'm sure Enna managed to sneak a visit to her one time and that she was one of the last collab partners before her graduation. I am more surprised by the fact Michi followed her publicly rather than doing it at all, as I thought ex-niji livers had to avoid all public contact with old coworkers, maybe it's because she's Ex-ID? or maybe she doesn't give a fuck about it?