Facebook is a pretty depressing read as well. The "it's just a joke" argument is particularly undermined by the fact that in recent weeks there's been a flurry of racist incidents in Scottish and English football. For all the work done in the last couple of decades, racism never went away; it's just that people are feeling emboldened to express these sorts of views again. Robson's behaviour is just an example of it.
If that Courier commentator's Nigerian friend does actually exist, he's probably unsurprised by this behaviour of a Dundee United player given what our team's name means in that country.
Griezmann's behaviour isn't really any better, although it doesn't have the same- likely unintentional given it's Robson after all - sneering mockery that's implicit in Robson's costume, which clearly belittles the figure he's dressing as and reinforces stereotypes. Look at how Robson's bulging his eyes in his photo not unlike the way minstrels typically do.
The more famous you are the more likely you are to avoid real punishment for this sort of behaviour; I don't think that's a particularly controversial statement.
However, that doesn't make it alright.
He may be young but this is the second serious incident with Robson in the space of a year, he's blown his chance. The fact he isn't playing and has been poor for over a year shouldn't come into it. We were endlessly tolerant to Goodwillie because he was an asset but he never ever learned.