Why are Americans generally more rude compared to the other English speaking countries except south africa?

I do it to make your life a living hell.

Our American friends are not rude, they are just from a different culture where different social norms apply. No one sets out to be knowingly rude.

Just as with anywhere else, there are wide regional variances. People from some areas are more forthright while people from other areas are more circumspect. Some people are very informal while others are more formal. Most American people have a strong sense of national identity and take pride in the USA. They come from a culture in which perceived performance matters so they learn to project more than we may be used to.

These are alien concepts in some English speaking countries. In the UK, for example, we are masters of understatement and we understand that what we DON'T say matters as much as what we DO say. That would just be baffling to some non-Brits.

Also, bear in mind that many of our American cousins have limited exposure to the world outside the USA. It's a big place so most will never need to know what goes on beyond the border. What they are shown in the media is filtered according to what the media company thinks the audience wants to see. As a consequence, they may leave the USA with some false impressions.

All the Americans I have met have been decent people - a bit different in their customs but well meaning. They may well have thought I was rude for not swapping my fork into my other hand to pass food to my mouth ...... It's just different customs.

South Africa has 11 official languages..

Many parts of the US have a bloodthirsty, barbaric culture. "It's a dog eat dog world out there. Eat them before they eat you." The nice are seen as weak.