Not really, you could still do a credit card guarantee and there is no canceling once booked, period, end of story unless there is a true emergency. It doesn't take any time to open the app on the phone and hit reserve now. An alternative might be a virtual queue, open the app when you are near the restaurant and check in...no reservations at all, they just tell you what the wait time at each restaurant is.That would force people to give up some of their valuable park time planning meals, though. It would also keep people from being able to make dinner reservations at the best restaurants if they weren't rope droppers.
You'd still have plenty of people who'd reserve & then ditch, as everyone would feel the need to reserve in the morning, and then lots of families would hit a wall before dinner time & leave...
Seriously this requires no planning at all, if the reservation route is used for same day, open the app while standing in line for a ride and book the reservation. All you need to do is tell what restaurant, what time and how many people. Since credit card info is saved in the MDE app, it is super simple and you don't even have to enter that information.
Now for those without smart phones it would be a little harder, they would need to go to one of the FP kiosks and book from there, but you can only do so much.
I know to people who are used to booking at 180 days out this seems crazy, but really it can work quite well, especially with all of the modern tech we have and really it would make everything far easier. Make FPs day of only as well and it works much, much better, you don't end up with local people booking FPs in case they decide to go to the parks in 30 days, which reduces the number of FPs available. If everything is day of only and in park items are restricted to just those that have been scanned into the park (or any park if they have park hoppers), all of the sudden there will be availability for almost everything throughout the entire day.