So reading all this, this is a really dumb decision by Disney. Make it harder to spend your money. Makes no sense at all. What if ADR goes down? I know many people who don't even have the app installed. Mom can't even install MDE because it doesn't support her old iPhone. Going to a kiosk and trying to type in a complex 12 character password that we probably don't have memorized is no good either. You do have strong passwords I hope! Lucky for us we don't make many ADR's since we know plenty of places to eat that take walk-ups and usually is cheaper.
This is going to come across as brutal. I can't really word this any other way but hope you'll understand that I'm not trying to be an .
This is your problem. The world has moved on, and the majority of people use computers, mobiles etc and 'get it'. It's no longer a vendors problem if a select few either refuse to learn, or can't learn how to use technology that is not new anymore, or hard to use, or hard to access, or expensive.
At some point they must move on.
Obviously the immediate thing we all assume is that this is cost cutting. It means they can give all those reservation CMs different jobs and reduce numbers a bit. This is most likely the reason, which is an inevitable part of business.
This all being said, you get ample time before your trip to sort this sort of thing out. Even if you do for some reason leave it till you get there, or do a last minute trip, all you need to do is go to guest services at your resort, or at a park and ask for help.
Put another way; the loss in bookings from those who can't/won't use MDE will be non-existant, as the restaurants are virtually always at the capacity they want them to be, plus there's almost always space for walk-ins. Unless you decide to rock up on the busiest few weeks of the year you rarely need a reservation at most anyway if you don't mind waiting 10-20 minutes.
The sky's not falling at all here I'm afraid.