[ALittleLight]

Maybe a compromise would be keeping the button to install the extension but add a link along the lines of "Don't want an extension?" that explains how you can use it without installing the extension and your reasons for the extension.

[richardsocher]

Thanks. THat's helpful feedback. We just added that below the extension button:

Don't like extensions? Click here to make it your default manually instead.

[detaro]

Why would I set a search engine as default of which I have no idea if it is any good?