Whenever I talk to people who founded a company, I often like to ask the prehistory questions 'When did you meet? How long have you been working before you started the company?' A bad answer is, 'We met at a networking event a week ago, and we started a company because we both want to be entrepreneurs.'
I think competition can make people stronger at whatever it is they're competing on. If we're competing in some athletic event for competitive swimmers, really intensely competing, it's likely that both of us will become better, but it's also quite possible we'll lose sight of what's truly valuable.