Ok so 9.0.1, 9.0.2 and 9.1 should include all the changes from 9.0? I don't see extensibility listed as part of 9 as it was there in 8, we don't see copy and paste listed as a feature as it was in 3 or iMessage from 5, etc ... I also don't believe extensibility was listed in 8.0.1 and other point releases. How far do you go.
Simple users aside. When you install an update it has release information and terms and conditions/agreement. It is the culture to blame if you don't read them.
I used the feature through the beta release it worked however broke my data in the final release song have turned it off. The break is with my carrier update so waiting for them to fix it.
There should be some way of warning users who make the jump to iOS 9. Extensibility didn't exactly cause people go over data limits did it?
This would have all been a non issue had apple thought it through properly.
Plenty of users will have read wifi assist, but not realised the meaning. None of the 20 or so people I have told so far to turn wifi assist for realised what it properly meant.
Plus - the assumption could be easily made that its an opt in feature. Not all features in iOS releases are actually automatically on, they are options so its perfectly reasonable for people to assume it was an option as it doesn't say "Wifi assist automatically enabled".