Well, it mainly depends on the meaning of "underrated"... and whose "rating" are used for a basis of comparison.
I think Jacques Plante being 3rd on the HOH Top-60 goalies list means he's underrated, but that's probably not the common sense of the word "underrated". Meanwhile, a guy like Dan Bouchard didn't make your list, but he was a goalie that was better than his teammates on a consistent basis and who never really got the chance to play for a team that had a shot at anything, with the remote exception of the Nordiques... and he was possibly past-prime then.
And Bouchard also never gets much consideration either. He had a better career than, say, Mike Palmateer, and was, in all likelyhood, a better player than him. Yet Palmateer's name is much more known.