We can argue all day long what is and what really isn't important. The fact is they decided it isn't and the backlash showed quite strongly that it was wrong.
What backlash? This same scenario seems to play out practically every month: Apple does something that generates tons of negative comments from — as far as I can tell — people who don't actually use Apple products (removes the headphone jack, throttles performance for phones with aging batteries, releases phone with minor antenna issue, replaces TouchID with FaceID, the notch on the iPhone X, USB-C MBP, etc.). The next quarter, they announce record sales and continue their absolute domination in terms of both customer satisfaction and profit share in the overall market.
The simple reality is that these things are never as big of an issue as people out for blood make them appear (antenna issue, headphone jack, the Notch), or most consumers actually generally agree with the stance taken by Apple (throttle phones with dying batteries rather than unexpected shutoffs, FaceID).
And honestly? I think they made the right call, even if the implementation details were off. Phones shutting off randomly is something that appears common on Android phones but not on iPhones, and throttling them to prevent this was the right decision to make. Warning that this is occurring is something that, in retrospect, was warranted. But it's easy to see how the teams in question for implementing this could have underestimated the performance impact, the scale of how many phones this would affect, or both. And it's easy to see how adding a warning might have been considered a v2 of the feature, whereas v1 was the quick band-aid needed to ship to prevent a problem that might have affected large numbers of phones in the wild.
In my opinion, Apple has so much goodwill built up from making difficult-but-principled decisions, I'm more than happy to give them the benefit of the doubt. If anything, their response reinforces my belief that they thought this was the right decision from the get-go. They didn't roll back the feature as other companies would have done. They stuck by it because it's the right move for the vast majority of their customers.
Everyone gets upset that their pet setting isn't available, but nobody stops to think about the consequences of having everyone else's pet setting available.