I remember working at an Optical Networking startup in Ottawa, where my boss, in particular, was extremely passionate, and believed deeply in the company, and consequently worked weekends and 18 - 20 hour days regularly. The company never got a customer, and went bankrupt. My boss got laid off with everyone else.
What is the lesson there? To give up passion and go through life jaded and without colour?
I also killed myself working for Ottawa start ups that failed. I decided that I should take more responsibility for a company's success and pushed myself to learn the business of software. Now I have some successful startups in my track record.
If your team lets you down that does not mean you should let yourself down.