> "then the workaholics could work more, learn more, and get paid more, whatever, and the just-a-jobbers could just work, and everyone would get paid by what they contribute."
Its not hard, its called contracting for an hourly wage. The problem is that many employers want workaholism at a 40hr a week wage.
It's not really possible here; the value of you going out and doing some unrelated pet project is much lower per-hour than working on an actual company project but it is non-zero. It's not like the company can look at what you are doing hour to hour and negotiate some random hourly amount that changes every hour.
Besides, hourly wage really doesn't make any sense for most jobs and certainly not software engineering. If someone works for 5 hours a day and gets more as much done as someone working 10 why would they get paid less? You could do some backwards math and come up with some hourly wage for the 5 hour guy but that's really just putting the cart before the horse.
Its not hard, its called contracting for an hourly wage. The problem is that many employers want workaholism at a 40hr a week wage.