As Solozo is explaining the attack on Vito Corleone to Michael, he says that it is not personal, it's business. What needs to be clear here is that it is in regards to the reaction. But the action that caused the reaction was very personal to Solozo.
But I find it often used in an incorrect context of the actual action.
What does this have to do with software development? We had a situation a few weeks back where a project had two people managing/leading it. And it didn't seem to make progress as was expected. I asked one of the leaders, who is also my colleague, if it was imperative for her to have this project done. And the reply was a reluctant no. That's when I knew that the project was headed nowhere.
A few years back, I was working on a project and discussing a complex scenario with my customer. After discussing possible solutions, she asked how in the world was this going to get done, given the resources and time. Then she said something that moved me to the guts. She said that she was so dependent on this project that she would be completely stranded if it didn't happen. I was so motivated to get the project done that I did everything that I could to take it to successful completion.
That's what I mean by that it has to be personal. If a project is not personal for at least one of the involved parties, it is never going to reach completion. That is what the difference is in the commitment of Founders vs Employees.
So, if it is not personal, it is just business. And if it is not personal, good luck getting it to successful completion. (But of course, the definition of 'successful completion' is subjective!)