If you are doing anything worthwhile, you will have critics. Learn to discern between those providing valuable feedback on your product or service and those who simply have too much time on their hands and a sour attitude.
How much can you reduce content marketing risk if your community can help come up with ideas to test? Or how might your crowd expand your network to reach early reference accounts or influential customers?
I believe that marketing is what you do when your product or service sucks or when you make so much profit on every marginal customer that it would be crazy to not spend a bit of that profit acquiring more of them (coke, zynga, bud, viagra).