WHAT'S OPERA, DOC? Terry Teachout's OpinionJournal complaint against the Ground Zero arts companies selections pretends to be a righteous jeremiad against "culture by committee." The recent theatre, dance, and museum choices are "modest and safe" and "very, very small," says Teachout, when the committee, had they any guts, could have made "the boldest possible declaration of faith in the power and glory of Western culture" by including Teachout's favored candidate, the New York City Opera.