I just wanted to point you to a discussion at EnWiki Village Pump: Recent_user_interface_change_discussion (permalink to likely-incomplete discussion).
I suspect(?) that they encountered the feature on a different language, and I assume they thought it would be most effective to contact us in Wikipedia's main/home language.
The key fragment is this: I just wanted to register how awful a change I think it is. I respect and commend the utility of the feature; my comments are solely about forcing it on people. Some of us specifically like the Wikipedia interface for its simplicity and lack of movement. An 80-year-old user I know specifically complains about "all that moving stuff" which prevents her using many sites.
I think it well embodies the prevailing editor view on EnWiki. The feature offers an obvious utility, but default gadgets&gizmos are awful. There's a broad view valuing a certain kind of simplicity for Wikipedia.