The rest of the world hates America because he takes advantage of his natural born rights for being a citizen?
No - people dislike American's for their irrational behavior and ignorant beliefs. Similar to what you just demonstrated.
As for the "Assault Rifle" - If he were to post up a picture of a Ruger Mini 14 you wouldn't give a damn, and it has all the same capabilities of an AR. He has the rifle - because he wants the rifle. Seems like a pretty basic concept to understand. That gun is no more dangerous than any other gun. Its the person behind the gun you worry about - and people like you are who are more dangerous with a firearm.