OK, while I am not in "love" with the FP+ system, I will attempt to tell you what I think were some problems with the previous FP system, a.k.a FP-:
1. As you mentioned, and it is a big deal for some, FPs would run out for certain attractions if a person was not in that park by a certain time at certain times of the year.
I understand this point. And I did see it as a problem at 2 or 3 rides but I still believe the current system still allowed for a much more level playing field. The only thing required was to be in the park before 10. Not nearly as many chances of leaving people out. The new system has the chance of leaving out day trippers, last minute planners, and those that do not use computers or smart phones. Because the chances of the FP+s running out days before hand at these rides during certain times of the year might be just a great.
2. It created an unnecessary secondary distribution channel for FPs that would cause a shortage for other users. People would pull FPs expressly for the purpose of giving to others. These people would be the ones who would to decide who would get an FP for certain rides where FPs were gone instead of the guest having a chance to pull their own FP.
Ok, I'll give you that one too but (see how I follow everything with a but? ) like you mentioned that not enough AP holders would go online to pre-book FP+ as a just in case, I don't believe that there was enough of this going on to make a huge impact on FPs. Yes, it did make some impact but so can AP holders taking FP+ spaces in case they decide to use them.
3. Paper tickets are a consumable which cost Disney money and from a "green" standpoint was not desirable.
Agreed!
4. It created crowd management issues
Since this hasn't been a concern for me. I have no idea how much truth there is in this.
5. It created supply issues with people pulling FPs that they "might" use at attractions where FPs would run out.
Okay, well how about IN TESTING (I know...not final) that it has been reported that they are requiring that you pre-book 3 FP+s. Even if you only want to use one. That is not an option at this time. That sounds just about the same as people pulling FPs that they "might" use.
6. Lastly, and probably most importantly from Disney's standpoint was that the FP- system was not producing the outcomes that they desired.
And this one may do the same. The way it seems to me and my family is the current system kept us in the park all day buying food and water and treats. The new system appears to have the affect of having our family cut out early. We have no reason to stick around after our FP+s are used and most of the headliners have long SB waits.
The FP- system was not without its issues. I didnt even mention pre-enforcement days which also created its own set of problems because those days are over but it does illustrate that there have been some problems with the FP- system over the course of time