You asked why do people be mean? what causes their meanness?
I shared 2 view points 1 biological and the latter environmental or psychological!
It is sad to me as well, that is why we need to be educated on all these issue so that we can know for ourselves and share with others, "so that we all can be the best that we can be!
There is no utopia, we will always have problems we just need to find the best way to address these problems ? I am not certain of the best way to address all of these problems but I am open to ideas!!