To do that you'd need airplanes you're allowed to spin and instructors willing to spin one themselves. You might be surprised at how challenging that can be in some locations.
I am more than willing to let students spin an airplane if they want to, but don't make them do it.
I agree that doing cross countries, especially longer ones, will provide a person with new challenges and make a person cope with them. I do not believe that is all there is to being a pilot however, and there are skills that can be learned locally that will never be learned by cruising straight and level for hours on end to get to a destination and make one landing, then turn around and come home. I'd honestly argue that aerobatic training, tailwheel training, spin training, and short "low n slow" cross countries using pilotage will likely produce a more well rounded pilot than one that has a bunch of cross country hours at altitude in a modern GPS equipped airplane.
Different people want to learn to fly for different reasons though. I try to tailor lessons to the kind of flying they want to do post PPL so they are proficient in those areas.
I think the agonizing over technical details is more of a personality thing. I've run across a lot of people who really don't want to know or be hassled by the rules and the technical details, all they want to do is fly an airplane and go where they want to. I've also worked with some people who will spend hours asking questions about every little detail about a flight or what to do in a certain hypothetical situation, to the point of paralysis and fear of doing the wrong thing.
I learned to fly in the last 10 years, so I don't know what it was like before that but there definitely is the expectation that you'll know a little bit about a lot of different subjects (aircraft systems, weather, aeromedical factors, airspace, etc.). That doesn't mean that you need to be an expert at everything, you just need to know enough to keep yourself out of trouble and know where to find the right answer if you don't know.