Avira, I agree it is legit, especially in our days, not to learn philosophy. Philosophy used to include all sciences (I am a D. of Ph. but did not have to learn Plato, just to come up with some new math formulae). So, at Rambam’s time it was the best science available. As your example shows – Rambam learned from Aristotle, liked his general wording, connected it to relevant chazal, corrected it, and it sounds like not even always quoted explicitly.
But in our times, we have an explosion of general knowledge that is very practical and specific and not speculative. Do you think Rambam would not attend a medical school now, when you don’t have to pretend to be a Muslim to get into first in the world university/madrasa in Fes? Obviously, we don’t need Talmidei Chachamim to drop their learning and all get into math and chemistry, but we need to stay connected with the world knowledge and have some Chachamim who can know enough to be able to converse with experts. And for those who have no clue of sciences, have decency to respect, and not disparage, those who do.
for a contemporary example, just heard a Rav describing what was lost/gained from Corona and he mentioned loss of respect to Rabbis as he said “while health departments were running schools”. I think this is abdication, talmidei chachamim should havev been in the forenfront of solving problems (and some were), and those who do not may have lost that respect for a good reason. And same happens in other cases. Let’s say a Rabbi does not understand how Gemora in Sukkah compute PI, is this good? It actually seems to be the case there – that Tannaitic computation is very precise, but Amoraim do not understand the Mishna and use more complicated solutions (inside circle, outside circle).