Personally I think it's wrong that if someone does anything out of character, immediately racism, feminism or sexist are used as excuses. I don't care if your black, white, green,purple, red or whatever, these excuses should not be defended or used as an argument.
Serena was purely wrong IMO and out of character. However, I do except apologies... I know in Formula 1, drivers are often over excited calling their other competitors as idiots, later they do apologies and admit it was of the heat of the moment. Those days of the likes of Mansell, Hunt and Schumacher hitting other drivers has been forgotten and in the past.
I don't think we'll see Serena ever apologies and it makes me sad that every black women out there has defended her over sexist or racist remarks are totally wrong IMO. This is a sport for goodness sake!... Not a bloody fiasco defending some rich multi-millionaire who got it wrong on the day.