Because many people for some reason don't strongly value the derivative of the solar inclination being zero and a local maximum within at most slightly over 30

Because many people for some reason don't strongly value the derivative of the solar inclination being zero and a local maximum within at most slightly over 30 minutes[1] of an analogue watch having the hands both vertical, on the few days a year that the equation of time is zero. [1] Because the equation of time might not be exactly zero at noon, the Earth isn't a perfect ovoid and you could be up to 7.5 degrees of longitude from the centre of an hour-wide timezone, even if you drew them perfectly straight down the globe with no regards to national borders.