Physics of today would be unrecognisable to a scientist at the start of the 20th century. Indeed the physics of 1935 would be unrecognisable to a scientist at the start of the 20th century. Our understanding progressed enormously AND it did so because people put forward radical theories in complete rupture with the established, 300-year old classical mechanics. There was no "traditionalist resistance" to it after it became apparent that classical mechanics failed to explain phenomena that quantum theory did explain.
>am astonished at how aggressively physicists resisted and suppressed "unconventional" interpretations of quantum mechanics (like the many worlds interpretation) in favor of the obviously-wrong Copenhagen interpretation [emphasis mine]
Ahahaha, you clearly have no idea what you're talking about. There is nothing "obviously wrong" about the standard Copenhagen interpretation (unless you have some new insight you would like to share), nor was there any suppression of ideas. Many debates have been waged in the past ~100 years, and many alternative interpretations have been put forward, like Bohmian theory, superdeterminism, or "shut-up-and-calculate".
>decided that it was meaningless to ask any deep questions about what QM actually meant
Physics, indeed all science, studies observable reality. Any "deep" questions about why or about things not measurable, quantifiable, or empirically observable, are by definition outside the scope of science. It is therefore as unreasonable as complaining about why don't geologists study epistemology. The answer is the same: it's outside the scope of their study.
I also don't like that your phrase seems to imply that what physicists study is not "deep" as opposed to your philosophical questions. There are many deep and beautiful ideas in physics.