It's also because it's more novel - and people love novelty.

But I think it's even moreso because, in a realist sense, the submarine fiasco was more preventable.

The wars and economic strife that cause people to flee their home countries in dangerous circumstances are such a large and timeless problem that people recognize them to be out of anyone's control.

But the decision of whether to take a rickety submarine to the ocean floor was totally within those people's locus of control. It wasn't part of some huge intractable problem, and was therefore entirely preventable. And because of that, it adds an embarrassment factor to the whole situation: it was their own fault that they died that way. It's more like a Greek tragedy, and captures people's attention in that way.