You know the expression: "Don't throw the baby out with the bathwater." It's an old expression; the first record of it dates back half a millennium. It's supposed to mean something like, don't get rid of something desirable while trying to eliminate something undesirable. It's a very common idiom, and I find I hear it a lot when discussing technological and social trends. Any time a critique arises about something, it's not too long before someone warns, "Don't throw the baby out with the bathwater." They don't want us to betray entirely the positive features of something just because there might be a problem with it.
But these days we drain baths rather than pour them out, so perhaps the expression has become confused. When people talk about not throwing the baby out with the bathwater, I find that what they really mean is something like, "Why is this baby in my bathtub? It's crying and wet and ... hang on, this isn't even my baby! Get it out of here so I can drain the tub and take a clean bath!"
As an expression about zeal, "don't throw the baby out with the bathwater" cuts both ways. In the usual sense, this expression admits that the (presumably spent, dirty) bathwater might need to go, but not with such zeal that the baby therein meets a similar fate. But it also works in reverse: we can have such zeal for whatever issue is metaphorically related to the bath as a whole that we'd sooner throw out the baby and keep the bathwater than admit that the two might not be so easily separated. Metaphors and idioms are good until they're not; more often the real issue is separating the grime and silt from the fresh water. Of course, once that dirty baby has been in it, it's a task easier said than done.
And when pressed, most people would sooner take a shower anyway.