The US throughout history has been responsible for some of mankind's finest achievements. You should be applauded for these. Humans walking on the moon, bringing democracy to many nations, inventions galore to increase human efficiency etc.
That being said, the US has become a country riddled with social issues, inequality, overcapitalism, warmongering, religious insanity, obesity, Iliteracy, unquestionable nationalism, obliviousNess to the outside world, etc.
The single worst thing about the US right now though is the mentality in a lot of its population, whether it be acts of greed or cruelty through the guise of religious justification, people who use fear as a means to further their own career or the celebrity clowns who will do just about anything to get famous so they can star in advertisements and rake in that sweet idiot money. All in all I think that most of the problems in the US lies in extremist capitalism...
This is not why most of the world hates you though. A lot of the hate comes from the arrogance you manage to show. A fitting example could be like when OP says america instead of US. It belittles the other countries there to a point where they don't even appear to matter.