I'm pretty sure the very similar numeric spinner issue on iOS has been around since Jobs was alive and running the show, so the idea that he would have reacted swiftly and decisively to an issue like this is not merely unverifiable speculation, but contrary to what (inconclusive, to be sure) evidence is available.
Since it's an alarm, as another comment has exemplified, you may actually miss an important event in your life because you didn't know to wait for an animation to complete before saving your alarm.
I would say that this is severe given the potential outcome.
Similarly, the calculator bug is more of an annoyance for people who know about it, which is already bad, but the problem really manifests to those who do not know about it and may end up, say, wiring the wrong amount in a money transfer because their phone calculator didn't finish the animation in time to register actual key presses.
This is UI making the outcome of user operations actually wrong, not just laggy.
It’s a damn shame. I loved the Apple of old.