Well, you have to take into account the travel season you are going in and the make up and ages of the people traveling. Can you show up at Disney with no ADRS and find somewhere to eat, or wait it out for a table or keep trying place after place? Sure. The question is, do you want to do that? I am a mother of 4 children and "winging it" and showing up and maybe getting a seat, or maybe not, or having to wait a long time is not a viable option for me. The thought of dragging my hungry children and husband from restaurant to restaurant, sounds like a form of torture. Also, with kids, you want to get those character meals booked as far in advance as possible. I mean, who wants to walk up to Chef Mickey's with your kids and be turned away? Not me. Plus, after this many trips, we all have our favorite meals and character meals and just showing up or trying for what ever is available would see like a big let down. Of course, this is our family, and what works for us.
Also, didn't mean to quote you on this post. I was talking in general what people need to take into consideration.