It's amazing to think of what Cousins could be if he didn't have the mentality of a 5 year old throwing a tantrum constantly...
He was fine until they fired their head coach without telling him. Mike Malone spent valuable time (years) developing a close relationship with Cousins and helping him mature. Cousins was very close with him, and the Kings were overachieving this year. Cousins had actually just put it together the past year and a half and was playing fantastic basketball with very few issues.
This would have been the basketball equivalent of firing Brad Stevens, letting Walter be the HC, and not telling any of the players. Imagine if Rondo was still here. He'd probably be irate. Heck, look at what Green looks like post-trading-best-player. Imagine if the coach was gone and no one told him!
Now, Cousins, the supposed face of the franchise that committed to a team long-term, finds out about a huge organizational move over Twitter? All he knows about the owner is that he wanted to play 4-on-5 defense and shoot three pointers. I wouldn't be happy if I was him, either.