A few thoughts regarding Holo bass:
1) "He is blaming this on Ame."
No. He specifically says Ame is not to blame and he holds no resentment for Ame or the charity stream.
2) "He was trying to take a cut or stop the charity."
No he wasn't. He said that would go against his conscience.
3) "The issue is that he tried to put the music on spotify."
He admits he was completely in the wrong there. But it is not the issue that led him to flip out to day. What happened is that he asked Cover for clarification: whether it was the dr seuss lyrics, or the character art, or Watson's voice etc. so he could address those concerns and hope to restore the tracks (by removing the offending elements, like changing the art). But Cover went completely silent.
4) "Cover is not legally required to respond to any of his inquiry. Their terms and guidelines are enough."
True. But by that logic, fans aren't legally required to continue their support either. Fans don't draw or compose due to legal requirements, but out of human passion. Cover left him on read, which made him realize he was always just some speck of dirt dependent on their mercy. Which is why he called it quits and wanted to go independent.
My own thoughts: both sides could have handled it better. The dude could have used his holo fame and goodwill to promote his own original works instead of burning the bridge and flipping out like a sperg. Cover could have handled this better by explaining their actions, not out of legal requirements, but simply to treat a small artist as a human being. It is not the first time Cover has frustrated an artist to the point of quitting, with their complete disregard (e.g. Mizuryu Kei). Also one other thing: too many teamates completely mischaracterized his actions, and painted it in the worst light possible. Unfortunately, that's how the internet works.