I certainly understand where Vic is coming from with regards to people not holding the same 'work ethic' or professional integrity as him. I think we probably have very similar opinions on that kind of thing - people not keeping promises or deadlines, pulling out of shoot dates with little notice to take on last minute paid work instead, or allowing involvement to sit on the back burner because its just not a priority for them.
However - I've found that when YOU have a passion project like this, other people are OBVIOUSLY going to hold different levels of regard for it. Some people think that the experience is the air that gives them life! Some people see it as just a bit of fun. Some people are only doing it because they owe you a favour. And some people are there because they are emotionally bound to because they're related to you.
Saying that though, I don't think that is limited to the difference between doing something for free (volunteering) and being paid. In my experience, people can be just as poorly organised on professional, paid shoots as well.