What a bizarre and egregious misstep.
With such unanimous disdain for this poorly thought out feature, and absolutely no acknowledgment to the overwhelming negative feedback received, I have to wonder what the strategy is here? Apparently this search unification is someone's pet project, and visionary as it may be, somehow claiming that the top of the menu bar as a "prominent and consistent" place for search, which as far as I know has never been used for search on any windowed UI, and not giving an option to revert this change is decidedly anti-customer. Was there any actual study or focus groups done on this change? Certainly, keep pursuing this "feature", but give the clear option to reinstate legacy search. The usage numbers would give a clear indication of what should be the default.