Really? I can't read a book unless I like the villain. Not sympathize, per se. But like: I need to think that they have a 3-dimensional personality, that they're realistically portrayed, that they consider themselves the heroes of their own stories and aren't just evil for the evilz.
I often still get intimidated by these villains. If I like the hero, too, then the villain threatening what they love is pretty much automatically intimidating.
But a likeable villain will keep me reading even if I don't like the hero, so I'm not intimidated by his actions. Usually I like laughing at the ways the stupid hero gets his butt kicked by the villain, and I'm sad when the idiot finally "wins."
But unless the hero is one of those amazing characters you just can't let go of... if I don't like the villain, I generally get bored and stop reading. Usually around the halfway mark.
So I don't think likeability and intimidation are mutually exclusive.
Well, it depends on what you mean by 'like'.
For example, I like the Joker as a villain in Batman Returns; he's a really interesting, engaging character. I sure as hell do not like him as a person, but for being a villain, he's gold. So you're right, likeability and intimidation aren't mutually exclusive.
But what I meant in my original comment was a villain being likeable because they were a likeable person who actually had very good motivations. I can't really fear anyone if I think they're in the right.