There are a lot of sad superhero origins out there, there aren’t a lot of superhero parents around, and those two facts are closely related. While Batman remains the gold standard for individuals who witnessed the demise of their parents and felt compelled to dress up in a costume to fight crime, his experience is not a particularly unique one in his line of work. As it turns out, there are a lot of other superheroes who have had to watch their folks perish - they just haven’t made it their whole thing.
Few make it to full-time superheroism without living through a harrowing superhero origin story, and many of those origin stories involve unspeakable tragedy. Sometimes, it’s the loss of a child, or a mentor, or a spouse that sets a hero off on their journey. But the majority of the time, it’s the loss of one or more parents, and often right before the very eyes of said superhero.
Or, in other words, Bruce Wayne ain’t all that special.