I have been critical of DuckDuckGo in the past, but it's the only one that promises privacy as a core feature. And if you couple it with a TOR browser or some anonymous proxy, you can hope for some privacy when doing sensitive searches.

A service like this doesn't need to be super popular. If it carves out an important niche, such as privacy aware users, then it can stay in the business and be a solid alternative for a long time. And they'll grow in market share too, they just need to stay afloat for long enough.