[mikeash]

This isn’t about battery life, it’s about sudden shutdowns. Older batteries can’t supply as much current. Apple limits performance to avoid pulling more current than the battery can supply. A bigger battery can supply more current.

People expect battery life to get worse as the battery ages. They don’t expect performance to get worse or for the phone to start shutting down spontaneously.

[pwinnski]

And yet that's what battery life getting worse does: spikes cause shutdowns. If people don't expect that, they don't know much about lithium-ion batteries. Which is fine, but that's exactly 100% what Apple is handling here.