I think that this framework isn't applicable to most because people who sincerely enjoy working are anomalous and in the minority. Even people who "love" their jobs do so not because the job is "lovable" in and of itself but because it is the lesser of all evils and affords them more freedom/time/benefits/money/other happiness-promoting factor, not because the actual labor is enjoyable in and of itself.
If most people were given a chance, they wouldn't elect to work. For most people, work is an obligation that they except reluctantly. Given this, "work-life balance" then becomes a unidirectional effort to drive down the amount of work and the number of hours down to zero, not to achieve any kind of real equilibrium.
Additionally, because hours worked is the most common and widely used method used to determine the amount of work one has done, any attempt to reduce that amount of work is most likely going to be done by reducing hours works. Hours are the quintessential "work measurement": if you want more "balance," you're going to try to work less hours.
I'm sorry, but most people don't like working, and they expend effort attempting to work less. Because of the widely accepted idea that hours worked equates to amount worked, the way that they do so is by trying to reduce their hours.
In the words of Micael Scott, "I would rather live jobless, on a beach somewhere, off the money from a large inheritance, than have to work in any one of these crapholes."
That's the mentality that most people have, and that's why they want to work fewer hours.