Simply put,
A liberal is a person who's just confused -- because he can't discriminate one thing from anything else.
You have it closest, IMO, in stating that they're confused. While I agree that liberals tend to support all those things listed in the essay, I think most of them don't have any guiding principles at all, how else could they endlessly support contradictory positions?
And if they didn't have a nice sounding buzz word like "liberal" to hide behind, but instead had to call themselves what they really are, supporters of socialism, then it might be less popular to be a "liberal." There's a basic dishonesty in the language which most are unaware of, I think.
Simply put,
A liberal is a person who's just confused -- because he can't discriminate one thing from anything else.
This sounds like an excuse and I, for one, wouldn't want to let them off this easy.