I can't speak for everyone, but whenever my facial hair gets long enough it's just a burlap sack on my face, full of itching and regret. It actually seems weird to me to do this to yourself just to be fashionable.
In your case, if you ever do grow a beard again, I recommend keeping your mustache trimmed. An untrimmed mustache is a substantially greater exercise in patience. You have to train the hairs to not creep into your mouth and, even then, there is a months-long period of time when the hairs aren't long enough to stay out of the way and eating anything wider than your mouth ends with you playing the "am I chewing on food or whiskers" game.
As for me, I grow a beard because 1) I can (thanks, genes plus work environment!) and 2) it keeps my face warm during northeast winters.