Killing them off can definitely work with the right plot, I just don't think they should bring them back if they do. Killing them off for no reason is a good way to show how powerful/amoral the villain is (for example) and even then movies don't have to be narratively satisfying to be good. The Texas Chainsaw Massacre ended with no sense of catharsis, which is the main reason the BBFC gave for banning it in the uk for 20 years, yet it's now praised for its unsatisfying ending, because it's unsatisfying ending is satisfying