I’m completely in favor of this change. It’s way past time for Google to have some competition anyway in the search market. The added privacy protection of DuckDuckGo is just icing on the cake.
I can’t find any fault with the GNOME project about this decision, given the recent disclosure of the NSA spying scandal that has sent shockwaves through the online world. Anything that helps protect the privacy of users is welcome, and I think other Linux projects should do the same thing (if they haven’t already moved away from Google).