The US is one of the most business friendly places in the world right now (it was before but more so now) another huge advantage is many skilled technical workers on the job market right now. If a company is considering a factory to produce plastic goods, sure, then China or any of the countries in SE Asia will be the logical choice, but for a highly technical production line the US has the skilled labor, and very business friendly environment (a lot of it by policies implemented in the current administration) non withstanding that Mitsubishi has a long history of production in the US.