The room-cleaning metaphor isn't as apt as you think. The metaphor I have found most helpful, heard from several other voices, is the garden-tending one.

There's a reductio ad absurdum open in the room-cleaning premise. I could write a million lines of code that don't do any measurable harm -- calling a no-op -- and by your standard they ought not be removed. Not doing any harm isn't the same as actively contributing value, which is what most people want their codebase to do.