Here are perhaps two of the best reasons why angel investors make sense for most businesses: 1) Angels invest for reasons other than pure economics, and 2) they tend to invest in industries they know or have worked in.
Here's an example of how these interrelated dynamics can work for you. A professional in New York City was contemplating chucking it all to start a sailing school, but he needed capital. Although this entrepreneur's idea might generate a nice profit, chances are it's not going to generate the kind of double-digit return that professional venture capitalists seek. In addition, the words "sailing school" aren't listed as an investment preference in any venture capital directory.
There are, however, entrepreneurs who have made it big in the boating industry and who may be motivated to invest, or at least hear an investment proposal, for a deeply rooted psychological reason: They want to provide a resource for others that they wish they'd had when they were bootstrapping their way to the top. So strong is this motivation that angels will often lower their required rate-of-return hurdles--not to the point where these returns challenge common sense, but clearly to the point where more companies can meet them--and a deal becomes viable.