I also think a large part of this is supply and demand.
If you are building the business, and have spare time to fill, you can be more flexible. Especially if you have multiple employees.
However for the majority of us, we have more customers than we need, which is always a good situation to be in. Any messers get left, and they either change their ways, or find another window cleaner who may accommodate.
That results in the best possible work day for us as business owners.
Maximising profit and minimising headaches.