I think everyone that doesn't like, should test themselves next time they visit.
Next time you visit, do your very best to not complain about it, but try it out for a day or two with an open mind. Return at the times your Fastpass says and enjoy the rest of your day as you normally would (or as best as possible).
See if it is easier than you though. See if you really do encounter tons of problems. As for those that typically leave the park for a nap, to park hop, for lunch, to get a drink, etc, see if you can find ways to still do that with the Fastpass times you recieve. If not, see if there are places in the parks that can equally provide rest and relaxation away from the typical theme park crowds. Find new traditions and ways around things.
If it all proves to be the worst vacation you have ever taken, well, then you can complain about how the new enforcement has been detrimental. If you find that is is more doable than you original thought, it just means that your future vacation might require a slight modification or two which really isn't a big deal when you account for other things like weather than can also force you to make modifications.
When my sister visited, we had Fastpass for Space Mountain in the morning, so we did stuff in Tomorrowland until our Fastpass. That worked out fine and we got a lot done. We then grabbed one for Peter Pan. We had 2-3 hours until we could use it. So we did Haunted Mansion, grabbed lunch, rode pirates, grabbed a Fastpass for Splash Mountain, and then made it back in time. We then split up, did a few other things. My sister and her friends were on Main Street shopping. I was over in Storybook Circus. I actually waiting 20 minutes to board the train over there, took a while to ride around, but we all still made it in our window. After that, they decided to go back to the hotel to rest and return later. With the Spring Break crowds (and a group of 8 of them), they were still able to get the following attractions done:
-Space Mountain
-Buzz Lightyear
-Monster Inc
-Haunted Mansion
-Pirates of the Caribbean
-Peter Pan's Flight
-Jungle Cruise
-Phillharmagic
-Splash Mountain
-Mad Tea Party
-Walt Disney World Railroad
-plus had time to shop, eat lunch, go back to the hotel an nap, watch the castle show, watch the Magic, memories, & you, and watch the fireworks.
That's pretty darn good.