Liza Jane B. answered 03/23/19
Lover of writing and teaching people how to write!
First pronouns are acceptable in academic writing. Most of my college professors either highly discouraged us using anything but first person or just didn't care either way. Most academic or research papers will have some form of "I" because it's almost virtually impossible to avoid it. Second person is rare or and not the easiest or smoothest to use, depending on the form and subject you're writing. It sounds like it's just the personal preference of your college professor because she finds it messy for some reason, was taught that herself, or that she was trying to expand your writing skills to not always rely on something you're comfortable with. Either way, I don't think it's something you should get points taken off for.
Hope this helps!