Looking at NBA, football and US sports in general, I don't believe that. These problems are usually more complex than "it's just racism". We have that kind of problems in Europe too.
Racists still enjoy sports. For them blacks athletes are like circus acts or monkeys performing for them -- they even have their favorites.
For me the difference is, that I live in the most dangerous city in Germany (statistic inflated due to giant airport) and would still walk through every street here at any time. I do not think that I would do the same in some parts of LA. So maybe my understanding of LA is a bit cartoonish - and granted you do not walk in LA anyway.
But they really aren't. There are more murders per capita in a quiet little town like Long Beach (CA) than in Naples (Italy).
Unfortunately that appears to work both ways.
The reason I do not plan to visit is because of that image about gun-totin', mentally unstable nation out of touch with reality with bizarre and secret laws which are in the worst case enforced by trigger-happy people with less than 5 months of training. Terrifying. But you aren't actually safe from them in a different continent either: attending to a wedding in Mid East can be lethal...
That's just classism, which is as bad as racism or xenophobia.
> different culture|religion|sexuality
Also inexcusable
> lower level of education
Which typically happens as a result of racism
> unpleasant behavior or physical appearance
Caused by poverty, which was caused by racism
Depends on the kind of classism (and the direction) -- because upper classes DO have power, money, etc, and it's not some basic human right or morality to believe that they should.
Else, we can describe anything with an "ism" and say it's bad. "You hate murderers? That's antimurderism".