@bornagainpenguin The menu is not what defines the desktop metaphor. The desktop, where you place icons and files, does that.
I've set out my rationale for making this change, no need to repeat myself.
You can only please most of the people most of the time. I am confident in my decision that this change, along with retaining the Traditional layout, is the right move. Judging by the feedback I've seen on the Ubuntu MATE social accounts, and here, most users commenting are happy to see this change too.
Your argument that a default is changing is weak since you know you can effortlessly restore the layout you prefer. I have no intention of removing the Traditional layout, there is no evidence to suggest I would. The number of layouts available in Ubuntu MATE continues to trend up.
You're right, defaults matter and this is precisely why I've made this change. The lack of Super key launching by default is a regular criticism I see leveled against Ubuntu MATE and it hurts adoption IMO.
Not sure why you're referring to posts about Compiz Fusion and Compiz Reloaded. Compiz 0.9 is shipped in Ubuntu MATE, offers first class MATE support and
gtk-window-decorator provides seamless theme integration. You can even enable Compiz with a single click via MATE Tweak. The Compiz plugins absent from Compiz 0.9 are missing because they don't offer OpenGL and EGL compatibility, if I we're to provide them it would cause Compiz to fail on ARM architectures. ARM is our biggest user base BTW. Compiz 0.9 has been working a treat in Ubuntu MATE for three years on multiple architectures. I follow the Compiz Reloaded project closely and see no reason to switch at this time.
I think your pessimism is misplaced and I hope you'll be a happy Ubuntu MATE 18.04 user with the Traditional layout