I want to be clear here. My experience of Chinese construction quality is that the most important factor is the reseller criteria. Price or quality based.
I have seen some absolute CRUD sold. The resellers blame the mfr - but it later transpires they beat them down on price and openly accepted poor quality. And more to the point did not really care - it is easy to simply replace the odd poor one than do proper QC.
This is a MONSTER problem with telescopic sights sold for AIRGUN use. No don't laugh - a spring airgun produces recoil harmonics that will shatter a sight that works on a 308WM.
Then there are others - who have a Chinese product, made well and priced accordingly - nobody wants it.
As for bits falling off - Harley had a real reputation for that in the UK as did Triumph etc. It was Honda that made us realise this was not a standard feature for 2 wheelers.
The Janus - well MAYBE the price has to do with them REALLY checking everything. And US labour costs apply.