I don't care enough about him to even hate him. I'd say he's more an annoyance (to the show audience, Ted is too good a person to show that little care to him) even than pitiable. You know how there are some people whose own issues drive their personality to where you can't even bring yourself to want to help them through their issues, or actively hate them? All you want is not to have to be around them because they're irritating?
That's how I feel about Nate.
Put even another way, Nate isn't a believable antagonist because his absurd issues make him unimportant enough that I can't bring myself to care about him.