I have a hard time imagining how a part-timers viewpoints and suggestions should be ignored simply because he is a "part timer". Shouldn't their viewpoint or suggestions be weighed on other scales? Just because they're part time doesn't automatically mean their stand or viewpoint is bad and should be avoided.
This is like saying an elderly person shouldn't be allowed to vote - because soon they'll be dead and they won't have any "skin in the game".
And where do you draw the line. Since you're judging ones source of revenue as someones "skin in the game", should a contractor's ideas whose business makes a million dollars a year be weighted heavier then a business owner whose business makes only 100,000 a year? Crazy. The guy who's making a 100,000 a year may be making more profit then the guy whose making a million.
Or what about a full-time pressure washing contractor whose spouse makes a 6 figure income every year. Or, maybe a pressure washing contractor has a multi-million dollar inheritance. All of the sudden.. they don't have any "skin in the game" - so let's ignore them.
Heck, I don't care if somebody is a landscaper, doctor, or dog groomer. If they have an idea that could better the industry as a whole, let's hear it.