To be fair, the abuse was still very different. GAC was an unlimited, immediate fast pass, essentially. No waiting for return times, no limits on rerides, given out like candy (I posted earlier in the thread of a man who was given one because he claimed he sometimes “wobbled” when he stood), etc. FPs were free, yes, but they still had their limitations which made the GAC very desirable to have to cheaters.
The switch to the DAS helped alleviate much of that abuse at first.
An aspect of GAC, FP paper, and even to some extent FP+ was that initially many parkgoers didn't know about them, or didn't know how to fully use them, or were not interested in power-using them. Many parkgoers did not seek a 4th FP+, and only used the 3 prebooked ones without modifying them.
Since G+ doesn't have the3 prebooks, and it costs $, it makes sense park goers would want to use more than 3 passes/day from the service. In the days of FP+, if you didn't feel like using a pass, you didn't lose and money. Missing an ILL purchase often means losing $20+/person.
MDE has changed dramatically over the years. When FP+ was new, it was only 3 passes, and it was a pain to modify them. Early on, the only way to modify a FP+ was to use the in-park kiosk. There was often a solid 20minute wait to use the kiosks, and there was not much worth choosing.
When MDE was new, it was pretty limited. FP modifying was mostly useless. It was only over time that refresh became worthwhile, and even longer before the masses learned how to refresh. Even then, many parkgoers were not interested in refreshing.
Parkgoer behavior and WDW's technology have changed dramatically since the days of GAC. Before the DDP, most diners did not pre-book most dining.