I haven't found that to be true.. Nationalists are pretty repulsive, but I think most transnational companies do appreciate patriotism.
Let's say there's problems in Chile with Copper Mines, or problems in Southeast Asia with Rubber Plantations, or problems in the Middle East with Oil Production, ... who you gonna' call?
I think it was Bismarck (maybe one of his Generals?) that said 'it's difficult to get Farmers to go and kill other Farmers'. So it is necessary to instill 'Nationalism' in the Lower Classes to go out and kill other people of the Lower Classes.
Why should MY Portfolio get dinged just because Evmetro (and his children) won't fight and die so I can make a Profit on a Global Scale?