>Mexico was sued because they effectively installed a tariff, not just because the law affected the profits of multinationals. They had agreed not to install such tariffs.
That agreement is still for not affecting the profits of multinationals...
(Though of course there is no shortage of "free-market-trumps-all" advocates to point out that such tarrifs hurt the local economy etc).
Sure, big companies are best positioned to take advantage of trade agreements. So what. It still makes sense to examine the totality of the impacts.
For example, I'm pretty curious about what impact NAFTA has had on illegal immigration from Mexico. Who knows if it has been significant, but surely it isn't zero (the number of illegal immigrants from Mexico is down substantially since it passed).