That's not necessarily true. Running a business means a lot of non-technical work that most developers can do without. For example, I don't think I'm lacking motivation or ambition, but I'm far happier building the technical foundation of somebody else's business and getting well paid for that, rather dealing with all the chores that running a business on my own would involve.

I think you are misusing the term "motivation" here, "ambition" is more fitting. But I agree with your point.

Every employee in any company or business is either building the foundation or part of the foundation of another person's business. Being a developer isn't any different.