Personal observation. Steven Weinberg made his career as an accomplished disciple of orthodox quantum theoretical physics, making it to the top of the physics/

Personal observation. Steven Weinberg made his career as an accomplished disciple of orthodox quantum theoretical physics, making it to the top of the physics/social food chain via hard work developing quantum field theory and getting acknowledged as one of the fathers of Standard Model. But all this without really "rocking the boat" of quantum theory. For a long time he believed quantum theory is fine and was not interested in the deeper questions about it. He eventually came around and realized and acknowledged that quantum theory has serious systemic problems of arbitrariness/internal consistency related to dichotomy unitary evolution/measurement, to dismay of some self-assured fanboys of QT orthodoxy. This gets him to the Feynman/Schwinger level, as in "did lots of great work, inspired lots of people, and realized the standard narratives have serious problems and wasn't afraid to say it and go his own way". His last textbook Lectures on Quantum Mechanics is one of the few extraordinarily notable textbooks on quantum theory that came out in last decades. If you want to get deeper into QT after you get through the standard superficial and hand-wavy college course, this is a very good and concise book.