The problem is that 100-minute hours isn't better than 60-minute hours by one particular metric: divisibility. 60 is highly composite (divisible by 2, 3, 4, 5,

The problem is that 100-minute hours isn't better than 60-minute hours by one particular metric: divisibility. 60 is highly composite (divisible by 2, 3, 4, 5, and 6), and one of the most common operations performed on an hour is division. Perhaps dividing an hour by 5 isn't particularly common, so 24 would have worked -- as such it's not surprising that there are 24 hours in a day. 24/60/60 weren't chosen willy-nilly, and replacing them with 10/100/100 isn't an improvement.