If Apple acquires a search engine, that engine will instantly lose most of its value. People do not want to use a search engine that appears to be a side-project.

What Apple should do, along with others in the industry, is jointly create and fund a new search engine, based on non-commercial principles.

I'll quote an old HN comment:

    > I don’t understand why Google’s competitors don’t form an 
    > independent search engine. If I were Microsoft, I’d talk to 
    > Apple and others to see if they would help fund a spun off Bing.
    > 
    > The internet badly needs a big alternative search engine that
    > isn’t beholden to advertisers or dependent on a single 
    > corporate owner.
    > 
    > The benefit of such a search engine (whose main incentive is to
    > just be a good search engine) is obvious for the public, but
    > would also give companies who rely on their own OS, leverage 
    > against Google.