Think is, it's the latter lessons that are correct, because the ultimate arbiter of which marketing practices work or not is the market itself.

If anything, Marketing 101 works as a scaffolding but you learn the real lessons later on (basically like with every other vocational training wrapped in a degree, including especially computer science) - but also, and perhaps more importantly, it serves as a fig leaf. You can point to that and say, it's a Science and an Art and is Principled and done well It Is For The Good Of All Mankind, and keep the veneer of legitimacy over what's in practice a more systematized way of bringing harm to your fellow humans.

Also specifically wrt. brands - brands as quality signals mostly died out a decade or more ago; mixing them up is just a way to get their decaying corpses to trick more people for a little longer.