I believe one in seven is the model of phone. I guess if you operational define “nothing wrong” as a failure to work as the manufacturer intended that would be true. But is that what really matters? What is the number of defects that should be counted? What number of six sigma defects would be counted?
The design of the phone is broken if 63% of the returns work as intended and customers still think they are broken. You might argue that the instructions are bad, but really shouldn’t people just be able to use the phone if it is designed well?
Yes that is a reasonable systems view that shows it is not just the design that can impact usability. But until the system provides good “training” to users you really should design something that is simple to use. And, even with good “training” for customers I really don’t see why you can’t design a phone to be easy to use.
Phones should be designed so that it is easy to do what at you want and hard to do what you don’t want. A form of poka-yoke.
Google offers wonderful webcasts of speeches available online by experts on engineering and other topics. In The Paradox of Choice – Why More Is Less, Barry Schwartz discusses related ideas and mentions the only kind of mobile phone you can’t get not is a simple one.