First comment before I begin: You get what you pay for. If you wanted FP+, you should have booked onsite.
1) It won't be this way for long. They will roll out FP+ booking to offsite guests eventually. They are testing this now with select guests.
2) According to Disney, 3 FastPass+ rides in a day is more than what guests averaged with FastPass-, which was 2. So unless you are a super planner with FP (which it sounds like you are) then this is an improvement for most causal guests.
3) Again, if/when offsite gets FP+ advanced booking, this need goes away.
4) There are a LOT of problems FP+ is designed to fix, the biggest one being rope-drop-runs to FP machines. It gives guests an opportunity to go on Tier 1 (E-Ticket) rides that they may usually miss out on. I'm not saying FP+ is perfect, but it's not created "just because".
5) Change is hard for most people to deal with. That is why old people long of the "good old days" when "everything was simply". It's not true, it just feels that way because change is hard.
6) It was always supposed to be strict. You were never really supposed to come after your hour window, but people ignored it and so did Disney. Now it's enforced and I personally think this is great.
7) True. Disney's answer is "book a longer stay if you want FP+ for all the tier 1 rides". Personally I think this is a business decision on Disney's part to get people to stay longer.
8) True. Technical issues are one of the downsides. What happens though is that you are automatically sent an email when a ride is down and you get a free FP+ for any time the rest of the day for a number of other rides listed in the email. This has happened to me twice.
One night Barnstormer went down and we got an email saying we could use it on 7 other rides, including Peter Pan's Flight, which had a 75 minute wait. We said OK! and walked right on that ride. The bonus is that it acted as a FORTH FP+.... our Barnstormer FP+ also still worked when the ride opened back up.