This was a necessary move.
Selfie sticks were banned for one reason:
All rides have a "sphere" around the ride vehicle (what they call the "envelope") that's free of props, supports, and objects. They determine the size of this envelope by considering the tallest person in the world reaching up with his hands -- and then a distance beyond that. If you look at the shape of the hole in the building that Hollywood RRR goes through... that's the envelope.
During ride testing, they will mount a device to the ride vehicle that reaches out into this envelope and they run the ride to ensure the device doesn't hit any objects.
The advent of the selfie stick introduces a new factor that was heretofore unthought of. Nobody ever imagined that people would be carrying extendable poles around in their pickets and wanting to use them on rides. The extendable pole exceeds the safety envelope. They can't expand the safety envelopes on all rides, so they just banned the sticks. Imagine if someone extends their selfie stick on Space Mountain, it hits a support, and the guest gets impaled. Not good.
So it has nothing to do with Disney not wanting people taking pictures of themselves, or getting poked in the eye from another guest standing in line.