don't throw the baby out with the bathwater
Don't discard something valuable or important while disposing of something worthless. Why are we scrapping the entire project? Come on, don't throw the baby out with the bathwater.
Don't throw the baby out with the bathwater.
Prov. Do not discard something valuable in your eagerness to get rid of some useless thing associated with it. Jill: As long as I'm selling all the books Grandpa had, I might s well sell the bookcases, too. Jane: Don't throw the baby out with the bathwater. You can use the bookcases for something else.