Nope. This is the realm of questionably and marginally viable products. Most experienced engineers are already working 40+ hours a week at high paying jobs, so

Nope. This is the realm of questionably and marginally viable products. Most experienced engineers are already working 40+ hours a week at high paying jobs, so we're talking about a the scraps of their spare time, and even that often comes with strings attached(experimental tech stacks, glacial delivery pace, etc.) Maybe add some time from marginal engineers(students, self taught no experience, overseas contractors). That's the supply. Demand often has no clue about tech, particularly custom software development, and often a very modest budget both in terms of cash and risk tolerance. That leads to two attempted solutions. The first is ODesk, which often fails and discourages further attempts. The second is entrepreneurship...engineers trying to find a problem that is solvable and felt by several hundred affected people/companies who they can actually manage to contact and sell to. This is a sales/marketing problem that most of us tend to ignore or fail at, especially those of us doing side projects where a major goal is playing with interesting tech. There's plenty of money being made in both solutions, but it's not the easy money people tend to think it is.