Academic philosophy is mostly concerned with the Greeks and Germans. The Romans had their philosophers, but they did not have the same influence on modern thought.
Also, often times philosophers do use an original word or phrase because it cannot be translated well into English. Language evolves over time and concepts as they were originally understood can be lost or muddled by modern uses of a word used to substitute. Also, etymology is more and more important in philosophy.
I read and write in academic philosophy for a living. Philosophers causally throw around Latin phrases in their writing (and, sometimes embarrassingly, even when speaking):
Many from historical figures (e.g., Kant's a priori/a posteriori, Berkeley's "esse ist percepi", Descartes "cogito ero sum", Leibniz's "salva veritate", etc.)
Forms/rules in logic (e.g., "modus ponens", "modus tollens", "reductio ad absurdum", etc.)
As well as a myriad of other commonly used terms you're expected to know when reading philosophy (e.g., prima facie, mutatis mutandis, a fortiori, eo ipso, ex nihilo, sui generis, ceteris paribus, ad hoc, non sequitur, etc. etc.).
This is not a random list. Every one of these Latin phrases sees heavy use in today's philosophical literature.
My favorite version of this is the person that you can tell is ITCHING to use that latin term they just found out about is arguing with a certified idiot. They keep dropping "argumentum ad hominem"s and "non sequitur"s at the idiot and the idiot doesn't know what it means or care and it goes on and on and on.