I'm sorry for your crappy experience OP. How they're handling offsite guests is shameful IMO and I hope it gets fixed soon.
Funny though, a couple months ago people were shouting from the rooftops how awesome FP+ is because you could even change headliners during the day during Christmas and NYE! Where'd all those people go? Those of us saying the true test will be when everyone is FP+ only were told we were being negative. I was there at the beginning of February when it was much slower, TSMM was gone about 1.5 hours into park opening, ETWB was gone as well as PP, on low crowd days. Awfully similar to FP-.
Truthfully I don't hate the system (but I would not go as an offsite guest at the moment), but people need to be real about what it is. It's not a magic system that makes FP easy to get for everything and everyone. The limitations are still there. People are still losing out. As many people have said, once offsite guests get their prebooking the running of the bulls for TSMM will happen slowly from 60 days out instead of right when the park opens and it will happen online, but it's still happening. Those who are not in the know lose out, just like they always did.
The problem can't be remedied until Disney increases desirable ride capacity, increases FP+ capacity at the mercy of stand by(please no!), or decreases the number of people in the parks. They can play with the numbers as much as they want, but at the end of the day someone is still losing out when there isn't enough ride space to go around. FP+ didn't fix anything, it put a band aid on the real issue. An issue that even a small chunk of that MM+ money could have helped.