This is a problem I have with the arms race of stakes-raising taking place in Hollywood movies right now. Dramatic stakes can't just be personal, they have to be global, galactic, universal, multi-versal. The bigger they get, the more numb the audience gets to it, which leads them to believe the answer is to go EVEN BIGGER, when the fact is, the bigger the calamity, the more abstract it becomes. Humans aren't wired to have strong emotional reactions to mass deaths outside their sphere of influence; if we were, we'd never get anything done. We respond to personal tragedy. Those we know, those we identify with, those we see ourselves in. We can sympathize with the other, but we don't grieve them, which is an important difference. To a movie-watching audience, an entire solar system being blown up affects us less than seeing Chewbacca getting shot in the arm, because we KNOW Chewbacca.
So ultimately, the only way for those planets being blown up to affect us is, like JB intimates, for us to watch it affect the characters we know. And for the characters to have had a realistically proportional reaction to it, it would have required grinding the plot to a halt, which simply isn't allowed to happen in a movie that Disney is expecting half a billion dollars out of on its opening weekend.