Lets say I want to ride Test Track and have a Fastpass. I use it, ride, and then I want to ride again. Now I have to wait 80 minutes because of Fastpass. Remove Fastpass completely and I would have waited something like 20 minutes each time instead. Its all a big catch-22 and Fastpass only gives you the illusion that you are benefiting from it.
Or, you could just do what I do for rides I like back to back rerides on, and wait until you collect two or three FPs and then ride back to back (to back!) with basically a walk-on time for each ride!
(Another option, of course, is to do the back to back rides right after rope drop without needing FP, but one cannot start with EVERYTHING in the first hour after rope drop, and FP is very helpful to get re-rides in these cases).
Personally, I love the system and find it EXPONENTIALLY increases my enjoyment of the parks.
Thanks to FP, I can go to the MK on the most crowded day of the year (such as New Year's Eve) and get on every attraction in the park and still have time to repeat favorites after that. This would be IMPOSSIBLE to do on a crowded day before the invention of FP! I remember the amount of rides/attractions I could do on a full day before FP, and know for a fact I can get on more now! In my case, at least, my benefit from FP is not an illusion; it's a reality!
Plus, I find it superior to EVERY other "virtual queue" system at other parks because it is FREE and DEMOCRATIC. It is available to EVERYONE regardless of whether you have an AP or a one day ticket. It is free to EVERYONE regardless of whether you are spending 200 bucks a night in a deluxe WDW resort, 200 bucks a week on Highway 192, or not spending ANYTHING on a hotel because you live in the area.
Since everyone has equal access, I feel no guilt whatsoever about utilizing the system to the fullest.
I find Fastpass actually INCREASES my ability to be "spontaneous" in the parks. If I want to ride a FP attraction in the middle of a crowded day, with minimal wait, I can now do so.
Regarding the idea that some have mentioned that using them past the one hour window is "breaking the rules", I have asked numerous Cast Members, ranging from entry-level, front line CMs, to coordinators, to MANAGEMENT about this, and there is NO RULE FORBIDING THIS. I have been clearly told by everyone I asked that Fastpasses DO NOT EXPIRE as long as you use it on the date printed on it, at any point AFTER the first time listed. The rules on the back of the ticket only state that they cannot be accepted early, and must be used on the date printed.
At the "Stars Of the Saga" show at Star Wars Weekends, 2010, the stormtroopers actually talked about this during the always-funny preshow! I may not remember the dialogue exactly, but it went something like this:
Trooper 1: I have to get out of here, I have a Fastpass for Toy Story Midway Mania!
Trooper 2: You can go later. They are good all day long, as long as you use them AFTER the first time listed.
Trooper 1: Really? I did not know that!
Trooper 2: Not a lot of people do!
As far as "negative effects" caused by people using them "late", IMO this all evens out. If someone has a one hour window between say, 12 and 1 PM, and doesn't show up at that time, this means the FP line was one person SHORTER between that hour and whenever the person does show up. So if they come back 6 hours later, 6 hours worth of standby people got on slightly quicker by the FP person coming back "late". By being "late" by six hours, one is, in effect, giving six hours worth of people "cuts", before returning to the line in front of people you are allowed to ride ahead of anyway, due to having the Fastpass acting as a "virtual placeholder" in the queue.
In my experience, when I use one "late", it is often more helpful to the standby queue than if I had been "on time".
For example, when I start with Fantasyland at Park Opening, I can usually finish the entire section in under 90 minutes right after the rope drops. Since this is my favorite section, I often grab a FP for Peter Pan's Flight and/or Pooh while I'm there in the morning, so that if I have time to repeat FL favorites during the magical night hours after I've finished the rest of the park, I know I'm set up with guaranteed walk-ons.
Now, to come back during the "one hour return time" would mean backtracking to attractions I've already ridden that day when I'm more interested in doing the sections and attractions I HAVEN'T done yet. It would also mean coming back to Pan and/or Pooh when the queue is packed in the late morning or early afternoon and being more of an inconvenience to those in the standby line.
But let's say I wait and revisit FL late at night, after the fireworks, during the last hour of the night. Most times Pooh is a walk-on, so I might not even need to use the FP. But if the line is backed up a little bit, having that FP in my pocket serves as "insurance" of a guaranteed walk-on and makes my last hour more "spontaneous" and magical by helping me avoid any waits and therefore get more late-night "goodbye rides" on favorite attractions. Same with Peter Pan, which is more likely to have a line during the last hour than Pooh. But if I do use the Peter Pan FP, this line is always MUCH shorter at this time than if I had ridden during the "One hour window", so by riding "late" in these cases, I'm actually inconveniencing FAR less people than I would have if I had used it during the first available hour when BOTH the standby and FP lines are MUCH more crowded.
I get the option of a guaranteed late night Peter Pan walk-on, which makes my last hour more "spontaneous" and magical; and all the people who waited in the standby and FP queues for the several hours before I used my FP got on ONE PERSON QUICKER because I DIDN'T use it "on time"! (And the people in back of me that last hour get on exactly when they would have had I used it earlier anyway, because I was technically ahead of them in line by virtue of having the Fastpass.)
I LOVE Disney's Fastpass system that ANYONE in the parks is free and welcome to enjoy. May it live FOREVER!!!!!