Hmm, is it giving Apple too much credit that they could slow down millions of iPhones at the same time the new models are released?
Relying on the linked article, not at all.
Their error was in not being open about what they did, because it really was
for the benefit of many users of (only relatively) old iPhones whom they could have treated the same way users of (really) old Macs are eventually treated.
Of course, though, if a new battery would suffice, what they did was kinda cold-hearted.