Why? Cause a stupid story called infinite crisis says so? Give me a break, am i supposed to hate wally west because of hic. Have you even read crisis on infinite earths? Prime lost his world and everything he knew. Yet, still he was optimistic enough to go with goldenage clois. Goldenage clois became his ma and pa.
He will be back to saving people. If harley the murderer extraordinaire can be "hero". Prime can as well.