I haven't really given it much thought.
Ordinarily, I'd say it was more about the writing than the actor but from what I've seen I thoroughly dislike the Adam character. I don't know MM personally but from what I've read, leads me to believe that both the character and the actor have a limited shelf life and could benefit from a change.
Like others have posted, although I don't care for the actor, I believe he's here to stay, at least for the duration of his new contract. And this latest Twitter feud that his post has ignited doesn't surprise me in the least-- I suspected that in the wake of his recent Emmy nomination, there'd be a risk of him being even more insufferable than usual.
I guess I can only hope that Lifetime or Hallmark fill up their slate with movies to cast him in or that Tyler Perry comes calling to cast him in one of his series and the end result will be that his suddenly very busy schedule will force him to take his talents elsewhere and off Y&R.