This season has had a lot of problems but I finally figured out why the character of Negan just isn't working. It's not the actor, who is doing what he can with what he's given.
In the comics, Negan is a chatterbox who is constantly swearing in rather inventive ways. No one else in the entire series has talked anything like him and it gives the character an energy and a cartoonish quality that contrasts his extreme brutality. TV Negan is saying a lot of the same things but without the colorful profanity it...all...moves...so...slowly. He comes off like The Governor on mood stabilizers.
They probably should have just had him fake swear all the time, "freak this" and "freak that," and embraced the larger-than-life ridiculousness of the guy.
Mike