I think there are plenty of reasons to hate America, although I would agree that at least here in Canada, alot of the anti-U.S. sentiment is baseless (insofar as most people themselves have little or no idea as to why they actually hate America).
America is a global bully. They are running around tearing down trade barriers, trying to open up new markets for themselves. But damn, if companies in other countries are actually benefitting from this by entering the U.S. market and they start competing with America's own producers, they are all over you, imposing taxes, tariffs, and whatever barriers they can, preventing your country from competing in their market. So then your country decides to play hardball by doing the same thing. Not gonna happen. The U.S. will sic the WTO all over you, imposing whatever economic sanctions and punishments they can. America - do as I say, not as I do.