I had the opposite experience in college. Most of my professors were pretty adamant that submitting .doc or .docx (or .pages or .rtf or .tex) files wasn't accep

I had the opposite experience in college. Most of my professors were pretty adamant that submitting .doc or .docx (or .pages or .rtf or .tex) files wasn't acceptable. You were supposed to export whatever your source file was to PDF, and submit that. Especially the case in my CS courses. Word was more common in the humanities courses, but I never had a problem submitting a PDF in those either, it just wasn't required. Besides accommodating profs who don't use Word (the CS dept had a small but vocal minority of Unix graybeards), the other main motivation was to avoid having to deal with version compatibility issues. Opening a document created on one version of Word in another version would often (depending on the version pair) mangle some things, especially references and cross-references. And some files just wouldn't open at all. Things might be better with that now; I haven't had occasion to investigate in a few years. In the 2000s, there was a huge mess with the .doc/.docx transition, as well as compatibility issues between the Windows and Mac versions of Office.