Has it fallen out of favor?
I love and hate Kant.
-I love him for attempting (and, I think, successfully defining) thought itself.
-I hate him for creating a lexicon of defining terms that, in the end, keep me guessing as to his actual meaning.
Kant holds audience with gentlemen like Wittgenstein and Heidegger. He posits ideas that demand an understanding of the framework of thought itself.
I don't think modern philosophical thought has departed from this. Perhaps, Philosophy momentarily takes leave of these defining ideas while in pursuit of more tangible conclusions. In the end, though, I think it always comes back to this type of foundational thought.