Undoubtedly, there are benefits in adopting non-discriminatory foreign investment policies similar to WTO most favoured nation provision. Economists and polling often, however, do not see eye to eye with each other. Pollies often take short term approach based on electoral pressures and will always find and use discrimination approaches to please powerful and vocal sections of the electorate. They probably don’t want to lose their power to do so.
On the other hand, economists argue for free trade. Yet the reality is there are enormous difficulties to negotiate really free trade agreements.