Its true nobody used to call it that, but then thats because, as far as I know, nobody KNEW it was called that. Its clearer to use "Goldsource" than "HL1" when referring to the engine, because HL1 could refer to either the engine or the game.
Of course thats all a load of bollocks really, as its normally pretty damn obvious which you are talking about, but I don't see any harm in using the "official" name now that it finally has one ![]()