I didn't mean to insinuate that every tragedy was guaranteed to be good. The post above answered mine by saying it depended on artistic merits. To both of you I say, yes, of course. All stories should be measured by how well they are told. Every piece of art rises or falls according to its execution.
But this thread isn't about that. It's about "rioting" because "something bad" happens to a character you love. Bad things have happened to all great characters, in and out of comic books. How they respond to adversity is the story in a superhero comic. (See: Oracle, pre-New 52) If nothing bad ever happens, what are they doing, playing cards or something? Having a birthday party? Taking a group hike? Every issue?
I get loving certain characters. I've been doing it all my life, like everyone. I just don't get freaking out if your favorite fictional characters are harmed in a fictional story. I'd actually be more upset if nothing bad ever happened to my favorite characters. That would make them flat characters and eventually they wouldn't be my favorites anymore.
But yes, a tragedy is only good if it is a good tragedy.
And yes, the success of a story depends on its artistic execution.
I'd have thought those things went without saying. I would have thought this went without saying too: a story where nothing bad ever happens to its hero is almost definitely gong to be a bad story.