This is an article I want to ponder, read again and ponder more. It looks like Jung (who I don't know a lot about) was the pot calling the kettle black.

I was struck how in the correspondence you quoted, Freud seemed much more "self-aware" and calm compared to Jung.

If Jung preferred science (even if he wasn't 100% empirical?) it seems clear why he lost interest in philosophers after Kant. The philosophers before that generally accepted science as platonically fundamental, as it seemed Jung did. (After Kant, loosely generalizing, the "analytics" came back to science, while the "continentals" never did.)

My uninformed impression is that Jung went beyond the empirical into the speculative (at least further than others in his field did). I've read some of Heidegger's later work, which I respect, and felt it was speculative and mystical. But I think he was speculating in part to stir other to think, which is a good thing.