[gumby]

It's a technology path dependence issue.

When towns had public mechanical clocks they were typically frequently adjusted (even daily) so that noon was when the sun was directly overhead.

Once railroads were developed their schedules were a mess since each time had to be in the time of the specific station. So the railroads got time zones introduced.

Then when the move for DST came around it had to be something easy to calculate, thus a one hour shift. Sort of like the Dow Jones: something that could be easily calculated by hand.