The captain had a remarkably good record of safety. This likely both helped cause the accident (it is believed he didn't react quickly enough) and helped make it shocking that it happened at all.
It was a civilian ship, so we likely have a fuller picture of what happened helping to make the story interesting. Military vessels often cannot have their full story told for reasons of national security. The most compelling details may be classified, removing juicy tidbits from the public record.
Enough people survived to tell the tale in substantial detail, giving us compelling tidbits like "the band played on." One survivor was a socialite who became known as The Unsinkable Molly Brown and her life inspired both plays and films.
https://en.m.wikipedia.org/wiki/Margaret_Brown
Some people see the sinking as an act of God, punishment for hubris because they bragged it was unsinkable. For people who want to believe in a spiritual view of things or karma, it's psychologically and emotionally compelling that they made the brag and then not only did it sink, it did so on the ship's maiden voyage. It's like a story a hack author would write to promote ideas like "Don't be a braggart, you foolish fool!" only it really happened.
