Writing in Spanish

I interviewed two professors in the Spanish department, and both of them gave me very similar answers. They both stressed that in a field that includes second language learners, professional training prohibits one from passing judgment on the errors that such students make in their work. With respect to native speakers in the Spanish major, there is no “correctness,” as Spanish speakers from different regions use different dialects, and the “mistakes” they make may be characteristic of the Spanish they learned while growing up.
As for a preferred writing style, professor 1 valued writing that communicates effectively and appropriately for its purpose, regardless of “proper” writing techniques. Professor 2 noted each student in the Spanish major speaks and writes at a different level, and placed emphasis on a student’s own recognition of repeated errors versus a professor continuously trying to correct the student.