After reading this post on Peter Suderman's blog and thinking back to some of the things that Jim Emerson has been writing about recently, I'm tempted to say that we're in the middle of a crisis of faith among film critics. Except that I'm not sure that this is anything new: film critics seem to have been in a crisis of faith for the last few years.
Peter is right: writing for a mass audience (i.e., in a daily paper) about the latest big budget comedy/action movie/chick flick does not require all that much knowledge about film history. Writing for an "educated" audience (i.e., in something like The New Yorker) requires a good deal more knowledge about film history, if only because your readers will expect you to put things in a larger context. Writing for an audience of film buffs (i.e., in something like Film Comment) requires a great deal of knowledge of film history, because fitting movies into that larger context is one of the major reasons magazines like that exist.
One of Peter's commenters wants to make the distinction between "reviewer" and "critic", and, though I don't think I've said this before, I think this is a bogus distinction. What matters is: who are you writing for? Who are you trying to engage with?
The problem with trying to separate "reviewer" from "critic" is that a lot of people who are writing about movies end up simultaneously reviewing (giving their opinion on the movie and suggesting what kind of audiences might find it appealing or otherwise) and doing criticism (giving their take on the movie and trying to place it into some kind of larger context).
With regard to Ronald Bergan's essay, I'd suggest that it's probably more important for film critics to put some work into learning about history in general and the history of other art forms (especially: visual arts, the novel, and the theater). Picking up film history is (comparatively) easy: the movies haven't been around that long and a couple of weekends of watching Criterion DVDs can get you up to speed pretty nicely.