The Nexus 5 had it shares of hardware issues when it launched:
http://bgr.com/2013/12/13/google-nexus-5-hardware-issues/. LG built the Nexus 5, LG had the Nexus 5 phone built in American and not China?
I have owned a iPhone 4S and now a iPhone 5, not a single hardware issue. Problems happen, on both cheap and expensive phones. Name one phone manufacturer that has not had some sort of hardware issue with their phones.
When manufacturing gets to the point that all phones are built by robots then maybe production issues can be elimated. But then that won't guarantee that parts won't fail and they do for whatever reason.