The primary purpose of this treaty is, essentially, to clarify the institutional process.  Treaties themselves are institutions that obligate, but don't guarantee, the changing of laws and regulations and ways of doing things among signatory countries. As political economists have noted, the record of the WTO actually leading to major changes among signatories domestic laws and regulations is pretty mixed, even when required by the treaty. Essentially the WTO works as little more than big political endorsement for pro-trade advocates in domestic contests over policies of all kinds, not as a force of law in any way.

But given the long, deep, and comprehensive nature of trade, communications, and investment between Europe and North America, I'm not sure why anyone would think an agreement like this should be opposed, a priori.  Why shouldn't Americans and Europeans get on the same page regarding regulation of commercial activity between them?