Can't argue economic reality as the other manufacturers setting up, or already there, can attest. The 'perceived' quality issue is just that and selective imo.
Well, this represents one of what may, or may not be example in support of that perception.
i'm not sure what a faulty fuel valve has to do with where the car is assembled...as i've said before, the robots and automation at the new plants in Mexico are the same as the ones used here, and throughout the USA...an ABB robot, a Schuler press and a Siemens PLC are all the same regardless of the country they're installed in.
As I was saying, it was reported in trade publications that Mazda had various quality control issues with everything being new - the plant, the workers, the suppliers, the relation with the suppliers. It's normal with a blank-sheet project such as this one, as Mazda did not have a foothold in Mexico prior to this. Like Nissan, GM, VW, Ford, FCA and others, things will improve over time.
I drove a Mexican-built Nissan for 6 years and it was pretty flawless, and I just bought another Mexican-built car, the Golf, probably the best-built vehicle I ever owned.