The manufacturers have made the decision to throw quality control out the window, and just ship their problems to the dealer and the buyer. And there's no excuse for it.
They can build them fast, as long as they actually inspect and repair issues, follow up with guys who make build errors, and (this is the real key) improve their process to make mistakes less likely to occur in the first place.
The auto manufacturers build a far more complex product with way fewer quality issues. It's not rocket science, the principles and methods of effective QC are well known.