That's a flawed analysis of the numbers. Maybe if everyone was riding exactly the same number of rides, and every standby line was always long, it might make sense, but that's not reality. You can't extrapolate out from an assumption that every person is riding the same rides they would have without FP+ or is waiting/not waiting in the same lines. The 80% number isn't huge, it doesn't mean anything.
80% of riders are now waiting by FastPass and not Standby "doesn't mean anything to you?" Well ok then there really isn't much to talk about if numbers like that are not meaningful to you.
Take any ride.
Space Mountain. Say it accommodates 20,000 riders. In FP- days:
4,000 people go FP- in 20 min (80,000 minutes)
16,000 people go Standby in 60 min (960,000 minutes)
Average wait time: 52 min
Now SB and FP+ lines are longer? Ok:
16,000 people go FP+ in 30 min (480,000 minutes)
4,000 people go Standby in 75 min (300,000 minutes)
Average wait time: 39 minutes
Can't you see? Although both the standby line and the fastpass line are longer, because now guests are 4:1 going by FastPass, waits are down. Guests are spending less time in line, on average, given some are spending more, but many more are spending less. The 20,000 riders who rode this yesterday, spent less total time in line than the 20,000 riders who rode it several years ago under FP- because they are mostly riding by FastPass now.
Disney was absolutely successful in getting guests out of the lines. Since the rides are almost all devoted to FP+ capacity. The TP revelation was so much wider acceptance than even I anticipated. I thought it was on the order of around 50% FP+ vs Standby, but they're saying 4:1 which is absolutely crazy usage levels. Now before you might have ridden Space Mountain twice in a day by FastPass (we sure did!) so we could ride twice in 40 min. Now you simply can't do that, Disney blocks you after the first riding, and ensures
everyone else that wanted to will get to ride once in the FP+ lane before you'll get a 2nd riding. But if you want to wait it out, you can ride twice in 30 min and then 75 min. You (and I) lose. But so many other guests win it is just crazy.