I most certainly agree with this statement. In addition, if it is likely that multiple people will read the letter, and the letter is impersonal, I think that the phrase is perfectly legitimate. "Dear Sir or Madam" is just a bit too personal for certain letters.
That said, situations in which this phrase must be used are undoubtedly rare. Still, in some cases, "To Whom It May Concern" is the best alternative.
As for "Yours faithfully," I might have seen this closing used once in my lifetime. The phrase "Sincerely" is much more common, at least in the U.S. (Or at least in Massachusetts.)