Are you doing any work outside the uni soon? I had friends studying medicine who were told they could either be clean shaven or have full, trimmed facial hair. They couldn't take part in off-campus or public-facing study with the intermediate stubbly phase, as patients interpret this as a lack of professionalism.
Check the small print for your course. It may mandate aspects of your personal appearance that other courses wouldn't care about.
Of course if it doesn't, then your lecturer can go whistle.