This. A thousand times this. A sense of professional pride is absolutely critical in becoming good at your craft, regardless of what that craft might be.
Right! Exactly! But would you agree that when you are working in an oursourcing company and projects change sometimes a few times per month - you are less motivated to think about being proud compared to just submitting the hours in time?
I think I understand your issue now. And yes, in that case I totally agree - all else being equal, an employee of the outsourcing company will care less about your success than your own employee.
But now you're comparing employees, not employees and contractors.
Young software engineers are easy to brainwash and convince to work long extra hours for free in startups. Contractors usually are the experienced startup employees of the past. They care less about the company's success because they know the company cares nothing about their success.
In my last two startups I had people over 40 working those long hours. A lot of contractors I know are lazy young guys that want the buck with minimum fuss.
Most contractors are experience ex-startupers - this sounds statistically incorrect ;)