Although I have only replaced two water pumps since 1956 (on a 1941 Chevy and a 1984 Impala), I agree that the difficult location on many cars with timing belts, the pumps should be replaced at a modest extra cost on those vehicles when the timing belt is done.
I was in an office once in New York, and an electrician was pulling out the all fluorescent tubes from the ceiling and putting them in a garbage bin. I asked the building manager why, and his answer was, "NY electrians are very expensive", so they extablished a projected time when most tubes would be past their 90% life expectancy, and then replaced them all at once rather than call in the world's most expensive electricians to replace them one at the time.
In pre-Thatcher England that task would require a licensed, unionized electrician PLUS a helper, an electrician in training. Never mind that in the US the average housewife or teenager knows how to do this without help.