I think the truth of the story behind FP+ changes likely lies somewhere in the middle. I don't believe for a second that Disney had no intentions of changing anything until guest feedback started rolling in. I also don't believe that Disney has had set plans from the start and not deviated from them or taken guest feedback into consideration. There are people on both sides of the debate claiming both of these things.
Either way, the way they've handled the rollout is IMO garbage. They have been very quiet about negative changes (like tiers, removal of KTTW cards etc.) while only being open about their positive changes (lock in your favourites, 4th FP is coming). Did I expect them to add the tiers "feature" into their ads? Of course not, but a little openness would have been nice when you're talking about serious impacts on people's vacations, like the unsuspecting Pop Century guests who arrived to find out they were the only guests not allowed to use FP-. I remember the days leading up to that people would call Disney and speak to the "front desk" at Pop, and were being told it was an internet rumour

.
Some of the people who are in the "just wait" camp seem to forget there were real actual people who vacationed with their real money during the last few months where FP+ was arguably at it's worst. Technical issues coupled with the most limiting form of FP+ (with tiers, without the 4th) wasn't exactly a party. Some of us don't get down to Disney multiple times a year, every year, every 2 years, etc. Maybe if Disney had been open about where this was headed, some of us may have been able to schedule our trips away from these few months. We may have tried had we known.
People love to remind others that the Dis members and other hardcore WDW fans are a small number in the parks. That's likely true. Since that's the case, how can you expect people to make themselves aware of something Disney wasn't even talking about?