Well, having read the book in question, I know that at least a portion of this article is highly misleading. But even admitting that a majority of the faculty and students are wacko leftists, Harvard College still provides one of the best undergraduate educations anywhere. Nowhere are you going to find a better qualified student body or faculty, and frankly, you're expected to disagree with your professors. A number of other schools generally provide equivalent academic environments, and a great number can provide equivalent educations to motivated students, but you're deluding yourself if you think Harvard isn't a top university.
That said, I'm not a graduate of the College, though I did get a couple of degrees from one of the graduate schools.