This is why we can't have nice things.
All kidding aside, but your idea is part of the current problem with dining at WDW. I am not saying YOU are the problem, or casting blame - this sounds like an innocent question.
Just to summarize history. At first dining at WDW was easy. Maybe make a reservation around noon, or just walk up if you didn't mind a 15 - 20 minute wait - max.
Then "free" dining started, and Disney started pushing the DDP at other times of the year. It got harder and harder to get into a restaurant. People still did not like the idea of having to decide 180 days out where they were going to eat, so people started to make multiple reservations. Restaurants were showing no availability, but people were not showing up. Disney got smart(ish) and started to check the logic and prevent you from making multiple reservations at the same time. People got smarter and started making dummy accounts. Disney got smarter again and started making you use a credit card to hold a reservation, and charging if you canceled with less than 24 hours notice.
So now were are where we are today. Either you make a reservation for what you really want, 180 days out. Or you wing it, and look for openings about 30 hours before you want to eat.
We could talk about the impact DDP has had on food quality as well, but that is a story for a different thread.
I don't think he/she was saying anything about making a dummy account... but for me to make some reservations on the days I didn't have ADRs I really wanted, and cancel them in the specified time.. etc. I'm not going to do that. What I am going to do is keep checking the app for reservations, especially during the busy times and see how it looks... so far, I've been checking every day for the day of and the day after... and this past week we could get reservations every day for some kind of dinner we would enjoy... So I'm thinking winging it will be fine for us, with the exception of the 3 adrs I will book in advance.