I think what most Americans arent getting responding to this is that, outside America, people's teams are their lives. They live and breathe everything to do with them. It's common to want your players to die on the pitch to get the victory, it's normal culture, especially in Europe and South America.
With this, it breeds an atmosphere where fans try and make it as uncomfortable and hostile for the other teams. The chants arent nice, youd never find pop songs being sung by fans, let alone by both sets of fans.
Thats why you shouldnt be surprised or offended at the fact a non American would look down and laugh at this sort of atmosphere, let alone the suggestion that it's better than our atmospheres.
For Americans, it's a fun occasion, for most of us, it's life or death