Interesting thread. I was in this hobby to a much larger degree when JJP was getting off the ground. At that time people were totally PO'd at Stern for shoddy quality compared to Bally/Williams and were holding up JJP to bring quality "back" to pinball. I got a NIB WOZ and all were impressed with quality.......until the LED board issues. I was pretty choked that I had this expensive (at the time 8k canadian for a new WOZ) that was IMO a lemon. Unloaded it and said I'd never buy a NIB JJP. So to see the discussion now - names have changed but seems like the same old same old.
I do think its pretty short sighted to not address these issues before they become issues - meaning catching them at the factory. You "MIGHT" be able to excuse Stern on poor build quality a decade ago - as a pin going on route........"what evs" right? But this hobby is now pretty much driven by individual hobbyists who are buying a game........... but also a piece of art, and they want it to be beautiful. And for the price being paid now - ya, they shouldn't be putting up with manufacturing defects like this. Again - maybe a electrical engineering defect (the lighting and boards on original WOZ were "new territory") on some new electric toy/effect.......but the recipe on fit and finish has had 25 plus years to perfect. So no real excuses for it to be happening.
I suppose to catch it at the factory would mean smaller batches with quality control on those smaller batches to prevent these issues making it to the customer - that in turn would likely drive up cost. To what degree not sure, and not sure anyone wants to pay even more TBH.