I have the same issue with Google Sheets. Non-experts don't understand how much of an impediment this is.
People need to watch a Shrekli video on YouTube to see how much some of us rely on the keyboard shortcuts.
You wouldn't expect a Vim user to just abandon their muscle memory and just switch to Emacs.
Expect to just abandon, no. Expect to spend a reasonable time learning and trying out the new interaction paradigm to see if it could (after controlling for unfamilliarity) also suit them, yes. (The ultimate answer may turn out to be negative, like for me in the case of Emacs.)
Abandon? Yes, no problem.
Switch back and forth? Now we're talking.
Same with switching from Qwerty to Colemak. That itself is large, but if it is a one way ticket it is doable. Problem is: the world (read: those using US keyboards) is made for Qwerty users.
Although the difference between modal and non-modal is rather large.
A compatibility layer like this, is for people who need to switch back and forth, and for whom it is better to stick with the Microsoft Office keybinds.
Took me about two weeks and I'm not looking back :)