What is More Severe, a Leak from a Water Distribution System or a Leak from a Sewer?

If to judge from the bulk of real time alerting technologies offered for the prevention of water losses, compared to simply none sewer leakage real time alerting technologies... the answer seems to be clear. 

Are we are being leaded by a concept that loss of money due to leaking drinking water is not acceptable, but making profit from getting rid of alarming percentages of public paid collected wastewater into sub- soil is OK??