Totally agree. My old design teacher gave me a "most creative" award for a project that was a total mess. It was nice to win, but that piece never went in my real portfolio.
Honestly, winning a local contest is cool and all, but is it really a big deal? Your professor is probably looking at the bigger picture for your career, not just a small win. Sometimes a design that gets a fun prize isn't actually that strong for a real portfolio. Maybe just take the win but also listen to the feedback.