Or so you would like us to believe. Most for profit crowdfunding schemes include some sort of levels that align with different benefits, (t-shirts, the product, etc.). So you are indeed "investing", as I say if you want to open a business, start small and grow it, anyone that funds anothers business is an idiot.
Pon·zi scheme
ˈpänzē ˌskēm/
noun
a form of fraud in which belief in the success of a nonexistent enterprise is fostered by the payment of quick returns to the first investors from money invested by later investors.
I really don't know what you're arguing. Ponzi schemes guaranty quick returns by using later investor's money to pay earlier investors. Nothing like crowd funding.