Its against manufacturing defects, and designed to fight planned obsolescence.

EDIT: Most warranties here don't cover consumer-caused damage either. If they do, extended warranty makes sense, but it's few and far between.

What goes into deciding reasonableness usually involves:

* Cost of product vs average income of average household

* Reliability advertised

* Average income of the targeted audience

* Audience reliance upon the product

As a quick example, an iPhone sells for about $1400, which is about 2% of the average income, and is a daily use item.

The device breaking causes disruption to the consumer, and has already cost a somewhat sizeable part of their income.

They're entitled to the time necessary to offset such a purchase, and interest rates and insurance rates are used as the guide here. Both of which use 4.8 years for 2%.