20 year UX veteran here. It's absolutely unheard of for UX to be the final arbiter on marketing &/or development driven features.

To take your 3D touch example. I'll bet it went a little something like this; development said 'we can now detect pressure', leads (inc UX) brainstormed on ways to utilise the functionality. Then it's soley on UX to make it usable.

I've never been involved in a situation where I get to demand capabilities that hitherto did not exist. Nor have I ever held the power to stop-ship. We have varying degrees of touch on functionality as it evolves for sure but not the power you assume we have.

We don't live in a reality where any company, Apple specifically, says 'hey customers, we realised we actually got things right on the last release, please give us more money 'cos shareholders'