Moruru had a reputation prior to joining Nijisanji of just creating personas and then scrapping them. So it was a mix of
>Some nijifans upset that YAGOO stole Moruru, some thought it was because she wanted a better model and others thought YAGOO gave a sweetheart contract>Some nijifans thinking it's Moruru doing her usual shit and that she'll retire from Hololive within the year>Some nijifans were absolutely livid that she didn't even attempt to change her persona going from Moruru to Luna>Some holofans thinking Niji contracts are shit if they let Moruru get away>Some nijifans immediately having a Scuddle moment at the mere mention of the previous oneApparently I still have this screenshot from back when Luna debuted
View attachment 26202
A lot of people didn't care though and were just happy that Moruru was back since she disappeared for like ~6 months after leaving Nijisanji.
I think it's best to say it's based on the specific person. Someone like Pomu would likely go to Hololive over Vshojo if she ever left Nijisanji because she's a idol-lover like Kiara.