I see the points about changes to iMessage, but that is fine, they are trying to ensure younger customers don't leave the Apple Eccosystem, hence possibly walk away from iOS devices. This makes sense. Good thing is you don't have to use these features, and if by chance a "young" person sends you a message, that is their choice.
Not sure what you were expecting from a platform that is now v10, however for me I think the new Notification Center is great, changes to notifications are in the right direction, the new lock screen changes are also excellent (fixing the camera access issues), news I might start using, Apple Music is now usable (was only using as I have a free subscription from my telco), major step forward with control centre, side by side in safari on ipad big tick, Siri changes are long overdue and will make me use it more, iMessages (not my fav changes, but understand why), photos app (might get me to use it), maps changes are dramatic (noticed this yesterday when using), HomeKit is something I now want to check out, anti-spam for inbound calls is good, voicemail transcription can't wait, the VoIP API to allow integration for Skype/FaceBook Messenger/etc, small changes in mail, ability to delete most stock apps, lock screen changes so I don't miss notifications with touchID getting so speedy, multi email compose on iPad, better iCloud Drive integration, continuity clipboard, international improvements for language support (type and Siri), markup in messages, better iPad Camera UI, live filters for photos, CarPlay improvements, rest and type for iPad keyboard, Apple Pay in browser, data detection and event finding in messages (like they had in mail) and a whole pile more.
Actually quite a pile of things when you look at it.
Not to mention some hidden things I'm sure that will enable the iPhone 7 when launched later in the year.