Companies exit geos (or never enter them) all the time. [1] No, it's not usually just about some law. But it may well have to do with nature of the market, regulatory climate, need to work through partners, cost of labor, work rules, etc. It's nothing to do with nationalist egos and everything to do with "it's just business" to avoid markets that aren't profitable or introduce too much business risk.

I really couldn't care less if there's some demand for my product/service in some market if it doesn't make business sense for me to sell there.

[1] For a random list. http://fortune.com/2015/01/16/international-retail-exits/