It's a similar issue to defence production. Unless we can offer something very attractive to a foreign company, like really cheap labour or some other 'hook', what is there to compel them to spend money to set up shop here for a comparatively small order book?
I don't necessarily agree that the required skills are the same. We build rail cars, but I don't believe we build power units anymore.
It is similar to our National Shipbuilding Program. We let the industry wither and are now trying to build it back up with gazillions of federal money in order to re-create an indigenous maritime industry. The one advantage in that case is ships take so long to build, and we are in such dire need of many hulls of multiple types that, hopefully, the industry doesn't wither again. Once VIA/HSR creates their modern fleet, what's left to build? Overseas orders? Maybe, if we have a marketable advantage that wins out against other countries trying to do the same thing.