I don't watch that channel or any of them anymore for that matter, but I see clips of Matthews every once in a while in news items I'm reading.  I think the man was going bonkers, you know, losing his mind.  He was so full of hate, on many levels, that I think he was driving himself nuts amongst other things (alzheimer's setting in or something wrong with his brain, for sure).  It was noteable and visible to those paying attention. 

MSDNC is better off without his anger, although they certainly have lots of it to go around!  If they aren't finding ways to belittle President Trump (and his family members) they just ain't happy - that's a fact.

https://thefederalist.com/2020/03/02/embattled-chris-matthews-resigns-suddenly-from-msnbc/

About the rest of the accusations against the man, I know nothing, but  he'll have time to address them now.