People aren't surprised that crappy overloaded rafts sink. But they're surprised that top-of-the-line yachts sink in a minor squall.
It's not confusing to me why one is more noteworthy than the other, technically. The wealth of the loss of life isn't really what's the difference here.
One death is a tragedy, ten thousand deaths is a statistic. Human psyche is built to understand death this way, don't pretend we are not. They are merely alluding to the fact that there are many millions of impossibly sad and tragic deaths daily. Why do we choose to care about some and not others? Abstraction is a necessary mechanism.