One framework that helps me a lot with these discussions is to treat a lot of rules and advice as directional rather than absolute. For instance, if you have an intern who gets stuck and spends a whole week trying to figure out something that a teammate would be able to work out with him in 30 minutes, you might say, "ask for advice when you get stuck". But if you have a different intern who bothers you all the time instead of trying to figure out anything on their own, you might say, "try and figure things out for yourself". These are contradictory pieces of advice, but they're meant for different people so they're not truly contradictory.

Pike's rules are very good directionally for a certain clever and diligent type of programmer who knows their CS fundamentals but sometimes overthinks what they're doing. If you are Rob Pike and you work places like Bell Labs or Google, you are going to be surrounded by more of these people and your advice is going to be directionally aimed at them. If you work with people who are sloppy or have poor CS fundamentals, you're going to want to give them different advice than Rob Pike gives his coworkers.

(In your example, people don't usually get as militantly stupid as Bar unless Foo is somehow antagonizing them or being too argumentative with his advice, which is a completely different aspect of giving advice. Either that, or Bar is a particular combination of "smart enough to rationalize their original position" and "stubborn enough not to give up their original position".)