Why are there sixty seconds in one minute and sixty minutes in one hour, but sixty hours do not equal one day?
Alan Longstaff provides an explanation for why minutes and hours are divided into sixty parts:
When the hour was divided into 60 minutes, consisting of 60 seconds, the number 60 was probably chosen for its mathematical convenience. It is divisible by a large number of smaller numbers without a remainder: 2, 3, 4, 5, 6, 10, 12, 15, 20 and 30.
He offers this explanation for why there are twenty-four parts in a day:
The Ancient Egyptians were the first to use 24 hours to divide the day. They divided the day into 12 hours from sunrise to sunset, and the night into a further 12 hours from sunset to sunrise.
The question, however, asks why are there not sixty hours in a day. Based on the Longstaff's information former astronomers made choices. Their successors followed those choices teaching them to the next generator. We are most recent in that tradition.
Longstaff A, "Why 12 months in a year, seven days in a week or 60 minutes in an hour?", Royal Museums Greenwich https://www.rmg.co.uk/discover/explore/why-12-months-year-seven-days-week-or-60-minutes-hour