That's not true; every manufacturer, including apple, does this. The question is simply to what degree. Battery chargers need to decide upto which voltage level to charge, and at which voltage level to consider a cell depleted; and similarly need to decide at which temperature to throttle during discharge - and at least as importantly - during charging. And it's not like it's got to cost and arm and a leg; even small amounts of additional headroom can likely prevent problems like apple's.
Basically: you can throttle after the battery is damaged or before. And if you throttle beforehand, you need to throttle a lot less.
Finally, you imply this is costly - but don't forget that apple's phones are amongst the most costly out there, and similar sized batteries are found in devices a small fraction of the cost. Clearly the bill of materials for the battery isn't a going to be a big deal for apple, compare to those competitors, which also happened to ship higher quality batteries.
Basically: you can throttle after the battery is damaged or before. And if you throttle beforehand, you need to throttle a lot less.
Finally, you imply this is costly - but don't forget that apple's phones are amongst the most costly out there, and similar sized batteries are found in devices a small fraction of the cost. Clearly the bill of materials for the battery isn't a going to be a big deal for apple, compare to those competitors, which also happened to ship higher quality batteries.