I agree with you, but after reading the article, I don't think the author is saying, "Put your idea on AngelList and if investors don't like it, don't do it." H

I agree with you, but after reading the article, I don't think the author is saying, "Put your idea on AngelList and if investors don't like it, don't do it." He used AngelList to connect with investors, and he used those investors to connect with actual customers (in his case, landlords, hotel managers, etc). So I don't think he's confusing investors with customers.