It's kind of two-fold.
On the one hand, she was tremendously talented, and she had other people connect with her (fans, who are complete strangers to her) because the beauty and purity of her voice. That's the power of art. It can be a really magical thing.
Also, she was in the public eye a lot. Increased awareness about her life and such.
On the other hand, I get what you're saying about soldiers and other people. It is kind of stupid. It's just that we live in a sensationalized, celebrit-ized society where the rich and famous are placed on pedestals. Think of all the idiots who degrade themselves to get on reality TV. Why do they do it? Fame, fortune, exposure, and a bunch of other shallow reasons. It's just the way the world is.
"don't think twice, it's alright"