Sunfish,
You are corect about fitness for purpose.
I used leading edges as an example because a ragged leading edge does make a huge difference to aerodynamic performance. One of the reasons Airbus aircraft are so much more fuel efficient than Boings. Not exactly a meaningless issue with fuel costs as they are.
Yep Boeing over engineer their aircraft and this makes build quality less important. Checkout the Zero fuel weight of an A320 and a 737 designed to carry the same amount of people. Not meaningless either.
I do have to agree with you however there is some guilding of the lilly which is unnecessary and Airbus quality standards have historically been too high for their own good. The reality is just like cars....if you want an over egineered , badly put together thirsty beast buy American. If you want something else pay a bit more and go for something from Japan/Germany etc.