[jyl]

It costs all of $60 to have a new iPhone battery professionally installed.

I don't get 90% of the vitriol. Would you prefer your older iPhone with a degraded battery start suddenly shutting off and become unusable? This iOS feature allows older iPhones, whose batteries have exceeded their charge cycles, remain usable, albeit slightly slower.

I do get 10% of the criticism. Apple could have, in addition to slowing the iPhone to keep it functioning, had it display an alert advising that the battery needs to be changed.