I resent this entire post. I like MM+ and I am as far removed from what you describe as you can get. I am an after-school and summer camp director who speaks and writes on the subject of NOT over-scheduling our children and reclaiming free play and childhood in general. I am a staunch believer that children in this day and age are being overburdened by parents trying to "fit in" one more lesson or practice in some attempt to perfect their children.
That being said, MM+ is NOT about that. It is about scheduling, organizing, and keeping track of a litany of details that the average park attendee finds overwhelming. ADRs, Fastpasses, whatever other things you plan for on the trip, all of these are (supposedly) easier to manage on MM+. From Disney's end, they get better data on us and how to get money out of us.
The difference in the two situations is also quite substantial. In daily life there isn't a finite resource on play and fun, you can go outside and engage nature or other children to make your own experiences. In WDW, that isn't the case, there are finite resources that are being overly-demanded, such as specific restaurants and attractions. To have a method for allocating those resources makes sense; that fact that you don't like the method is irrelevant, it is just as good a method as any other (depending on your perspective).
You can hate on the program all you want, but please leave your personal hang-ups about how your DSIL is raising your nieces and nephews out of it. As far as checking out from reality, I fail to see how you couldn't still enjoy the parks without using MM+, you just might not get to eat where you want or ride everything without a wait. Or maybe, you want to have the best of both worlds, spontaneity and access, and you are just mad that you can't have them simultaneously.
