what you want to do in a day, so you have to come back again or stay longer. I think the entire system was developed for the first timers and/or once in a lifetime or once every few years individual or family.
I know since we are AP holders and regulars we look at our vacations at WDW a whole lot different than my friends and family that only plan on going once in their lifetime. They want to commando the parks hitting every major attraction once, checking it off the list and moving on. And the new FP+ enables them to do just that. in a 7-8 day period they can book 21/24 FPs - counting all four parks there are 25 (give or take) major D or E ticket attractions. So, in a week's time you can get a single FP for each of these, do the minor ones and some of the majors that usually do not require a FP and go home very happy and think FP+ is the greatest thing since "free dining" (But, I am not going to go there).
For those of us who like to "wing it" take the first bus to arrive at the park and ride what we choose and want to ride our favorites over and over it is a big negative.

Yes, we will be able to ride our favs over and over, but probably not as much in the past. We will have to plan ahead to get what we want each day. I really dislike the tier, but then again this system is making stand-by lines where they didn't exist in the past. So now you will need a FP to get on Spaceship Earth at 6:00pm where before it was a walk on. Disney gets better crowd control as they can add and subtract FPs as they feel is necessary to move the crowds where they want them to go. I read where thy are hoping that with the installment of the entire $1Billion MyDisney Experience system every guest will spend an additional 10% at the resort. With those calculations they will be in the red in no time at all.
My fear is they did not take into consideration that the "regulars" may get fed up and quit coming back.

My family already has decided that this will be our last set of APs for a few years and we will wait until Avatarland opens to return. And even this Summer we cut our WDW time down 4 nights/5 Days and decided to go and stay on property at Universal.
They can continue to tweak it as necessary and if they see the park $$$ start to decrease I am sure they will. BUT, right now Park profits are soaring and they will continue to make business decisions over guest pleasures and experiences. Face it they put out $15 million in an attraction, they may get an initial small bump in attendance, but if they can pull in an extra 10% off each guest every stay and they are making even more money.
They know Disneyoids/freaks are very dedicated and will usually keep coming back no matter how much they complain, whine and grump. I seen a lot of these on this site and others, but honestly have many times did you see someone actually saying they are cancelling their vacation plans? Not too many.
Just the way I see it. As a Disney stock holder, I am excited to see record profits as a frequent guest I absolutely hate the new system.