Global Economy.
All that’s really necessary for them is a physical presence in the continental US for Repair, warranty, distribution and warehousing. The management and executive side of the company can be anywhere.
For the last 17 years I’ve done IT support for a massive financial institution. I worked from home full time. As long as I had an Internet connection, I could be on a beach in Cozumel, a ski lodge in Colorado, on my sailboat in the marina, in my underwear on the couch. Didn’t matter. I worked with US teams, India teams, UK, Japan, Germany.... all via video conference, teleconference, MOC (instant message), email.....and we could be working on a server in Florida or a data center in London. The only time when time of day came into play was with India shift change....if any of them missed a train they’d have to hire a $$$ cab ride home. Otherwise we were worldwide, 24x7x365. It’s really cool to have a videoconference session with San Francisco, Hyderabad and Virginia while we make live changes to a server solution in Kansas City.
Unless they stop marketing in the US or fail to innovate, I wouldn’t worry.