Tough to hire and train a population (Springfield area) that doesn't have a recent history/talent for manufacturing. Our state legislature mandated they're assembled here without considering the consequences (or they did, and didn't care).
They were also disqualified from bidding by the MBTA on the basis of quality, but as alluded above, they bought the winning firm, so theres no reason to believe they'll do well in quality control.
They also have little to no incentive to perform well in the US, especially now, and haven't really tried since they got here.