I'm pretty sure we addressed this somewhere in the 100+ page thread.. But this would possibly encourage kicking 1st timers or leaving if 1st timers were in the run.
Why? It's in the roulette to allow people progression clears and story completion. The actual rewards for doing it are pretty minimal without the huge roulette boost and there's no reason to give the boost if you allow skipping, this would create a crazy shortcut to leveling. Simply don't do this roulette if you aren't ok with the time investment vs the rewards.
.. usually was? It has always had the cutscenes since release. I also wouldn't consider going back to rework this a worthwhile investment of time vs working on new content everyone will enjoy. We've constantly been shown a limited resource pool for development being a thing with FFXIV, lets not sacrifice another instance or storyline to fix something that's easily ignorable and avoidable if you don't want to experience it more than once.