I was lucky enough to see an original cast performance in 1987 by lining up for a couple of hours for same-day tickets. (I saw eight performances in eight days that way, and Phantom was the most expensive, at GBP 18.)

As I recall, the Phantom was a compelling character, but not a romantic one. It's classic stalker logic: if I can't have you, no one will. Along with the trope of "I made you, therefore I own you."