I agree. The only people I read about (in blogs and trip reports) enjoying a relaxing and spontaneous time at WDW any more are guests who visit so often, and have been so many times, that they have no problem spending an entire day doing 3 attractions, eating a few snacks, and strolling and shopping.
I don't knock that approach a bit, but if you're an infrequent visitor, or a parent trying to satisfy a to-do list for multiple people, and the goal is to experience most or all of the attractions in a park without spending half your day in long lines, you've got to have a strategic plan, as well as encyclopedic knowledge of crowd flow, rope drop priorities, show schedules, Genie+ availability, virtual queuing procedures and timelines, etc. so you can make smart decisions on the fly when you have to inevitably have to depart from that plan.
Again I say I distinguish between plan and strategy, and I don't know we are far off...but we do try to wing it as much as possible.
We have been enough times that we are willing to gamble a little; we're not crushed if we miss 1 attraction. These days, it is pretty common for an attraction to be down.
But being spontaneous, in my view of park touring, doesn't = stopping after 3 rides, except for some Epcot days. Back when the Flower Festival was exciting, for example, we sometimes spent much of the day trying to see all the floral/festival displays. We usually spent 2 days in Epcot, where 1 was more focused on rides and the second was less focused on rides.
That said, we generally don't plan to watch the parade for example, but we often happen upon it when we are walking between attractions. On our most recent visit, we stopped to hear Voices of Liberty perform, because we just happened to be walking by when they were performing, that is one of the things we enjoy about WDW, or at least have enjoyed. There is/was always something new to see. At any given moment, there are multiple things to do/see. Each visit is a bit unique. If we happen upon something unusual/unique, we try to spontaneously enjoy it. To me, it is some of the unexpected aspects of WDW that make it worth visiting at all. The highlight of some trips is seeing young child's smile.
I also agree, most visits, something doesn't go as planned, and knowing strategic options is often the best approach.
Mostly what I'm trying to say is that I might say we don't plan, but that doesn't mean our net result is all that different from yours. We usually end up covering a long list of attractions, and our days are very full of activity.