There are angel investors in Silicon Valley (and elsewhere) who focus on smaller but less risky wins. It's not a horrible strategy, I think, if you make only a few investments and do it for reasons other than getting rich.
(If I were in a position to invest, I'd be happy investing in businesses which were sustainable/profitable but not the next $500mm exit IFF I wanted the beneficial side effects of those businesses. Even down to the scale of a single individual, sort of the "patronage" model. I think it's entirely reasonable that a single person could accomplish great solutions to small to midsize problems, like say a good zerocoin implementation. Sadly, I'm not right now, and probably won't be for several years.)
Plenty of angels seem happy with longer term or potentially ongoing revenue streams -- the kind of people who invest in restaurants, dry cleaners, consultancies, etc. Seems like it only makes sense if you really like the industry/product or the team, though.