Has this Menu-to-Customizer move been thoroughly tested, for instance, with multilingual WordPress installations? What about complex navigation systems, like we often see in WordPress themes? Were there real people testing it? How many? For how long?

I'm very disappointed by this move, this “let's just ignore criticism and call it resistance or education issue” IS NOT the WordPress Community way.

I know WordPress is all for “decisions not options”, but that applies to stuff that doesn't work. So I'm expecting this guys, who're clear making a huge mistake and are ignoring a large portion of active users, take a step back and, at least, keep the Menus screen alive and let common mortals use WordPress as theirs, not the UI team's.