That's the problem, nobody has yet created an -actual- competitive, viable alternative for the Office suite (not just bits and pieces of it, not just "basic functionality" but something that a company or individual could actually live and operate with, and collab with people who ARE using the Office suite without having to jump through hoops or deal with compatibility/conversion issues etc.). So you're right, there really is no viable competition. Some people get mad enough that they learn to live with an alternative like L----Office (so funny they don't even allow saying the name of a competing product on here) for the basic Office stack or some alternative note-taking tool for OneNote, but they all have drawbacks and caveats. Not that ON doesn't of course, but I think in many ways it's still the best product out there.
BTW, couldn't you choose to change the ribbon view back to menus in Office at least until recently?
My main gripe with this isn't even the fact that they just made a random change out of nowhere that nobody requested, for no apparent reason, but rather that they did so in a mandatory way with no opt-out feature. This (as with any significant UI change, and yes even a single box moving can be "significant" if its for a core feature like Search) really should have been an opt-in feature where by default it remained where it was unless the user chose to enable the new behavior. Or if anything maybe enable it if the user is using vertical tabs, but not if using horizontal (because as pointed out in many posts, with horizontal tabs there's literally no screen space gained which is the only perceived benefit).
But at the end of the day you're right. They will most likely ignore all the angry users until people get busy enough with their everyday lives to move on (because not everyone can spend their day keeping up on threads and discussions on whether MS decides to roll back an unwanted change), then after a while they'll close the comments or thread claiming lack of interest. That's generally how it goes.
Once in a while though, you make enough noise and something will actually change. Remember there was a time when they were going to kill off OneNote completely, and even published articles and guidance telling people to move to other solutions (such as the POS Win10 UWP OneNote)...and there was so much backlash worldwide they were eventually forced to relent and bring it back, and now its under active development again. That was admittedly the exception and not the rule, but it just goes to show feedback can make a difference. I'd encourage folks to continue offering your opinion whenever possible, whether MS wants it or not =)