Comment by bloppe

Car safety is a bad counterexample because the risk is otherwise often externalized i.e. your car can easily hurt a total stranger whereas the consequences of your choice in laptop are strictly personal. And as GP stated, regulating this sort of thing would definitely force a particular trade-off on everyone. A lot of people would be pissed to have MacBooks with worse "build quality" even if they were more reparable. Having a choice is better.