For starters, we don't need more x is not the same thing as saying we have too many x.
Why exactly do we need more cops? Is there a sudden rise in crime? Why, no, in fact there has been a substantial
decrease in violent crime over the last 20 years, off about a third since its peak.
Why do we need more firefighters? Is there a sudden rise in home fires? Nope, in fact there has been a
substantial drop in home fires and deaths from home fires; about half as many as there were 30 years ago.
Do we really need more teachers? The
number of public school teachers has grown quite substantially over the last 20 years and is projected to continue growing.