Comment by ChuckMcM
That's the correct answer, IBM wanted the crawler mostly to feed Watson. Building a full search engine (crawler, indexer, ranker, API, web application) for the English language was a hell of an accomplishment but by the time Blekko was acquired Google was paying out tens of billions of dollars to people to send them and only them their search queries. For a service that nominally has to live on advertising revenue getting humans to use it was the only way to be net profitable, and you can't spend billions buying traffic and hope to make it back on advertising as the #3 search engine in the English speaking markets.
There are other ways to monetize search (look at Kagi for example) than advertising. Blekko missed that window though. (too early, Google needed to get a crappy as it is today to make the value of a spam free search engine desirable)
Blekko was gone by the time I learned about it. Recently (past few years) I emailed someone who worked on Blekko to get his opinion on a search engine concept I still have yet to start. His advice was to not bother competing with Google (obviously) LOL!
I don’t know if anyone’s embarked on a P2P search engine but that’s essentially my concept. Anyhoo, thanks for the inspiration!