You're wrong, there aren't much worse things in the world than racism or any sort of discrimination. There are, however, much worse ways for it to manifest itself and that's why he got a month that will be reduced to community service on appeal. It's not a willy waving contest and, to be blunt, what happens in america has no relevance in Britain.
We have our laws, you break them, you get punished and the judge made it perfectly clear as to why he gave the sentence that he did. As a 21 year member of society, if Stacey is big enough to post about hanging niggers from trees and all sorts of other things, he's big enough to take his justified punishment.