Advice in poker is never absolute, but I'd say that it's definitely better for a beginner player to be given incomplete advice that applies 80% of the time than to go on their own and get it wrong 80% of the time. You can't master things until you're clear with the fundament, so while "raise or fold" is not correct in the slightest, it is better than just letting a beginner do what beginners usually do - which is call whenever they have anything slightly decent and raise whenever they have a monster hand. One can easily go from an absolute beginner to a "winning" player in most games in just a month or two just from some incomplete advice, because it's better than what most people do. The real challenge in poker is going from being just about a winning player to a player who consistently cashes in tournaments and regularly visits the final table.