Making units more disposable makes perfect commercial sense. Making them overtly more disposable might figure out into customer decisions which would be bad for profits. Better be subtle about it.
In that regard, not slowing down the devices with degraded batteries would have been substantially better. The behavior before was substantially more annoying: The phone would just shut down.
That would have led to bad publicity. Worse, people could have figured out by themselves the batteries were the problem. The trick is to annoy users, not make their workflow entirely impossible, and than to give them misleading advice so they'd buy a new phone.