Do we know the nature of the racist abuse? Was it a torrent of vile racist abuse throughout the match? Was it one word spoken in anger - yes, wrong, but I see that as different to the former. I'm not sure how these things are judged in law?
Anyway, there should be no room for racism, so whatever it was, it was enough for him to go before a magistrate and be punished.
At that point, if the court saw fit for a three year ban, I'm not sure why we feel the need to pile more punishment on top? Without knowing the details, I'd like to see the following sequence enacted: punishment, education, rehabilitation.
Punishment - the ban
Education - a suitable course, plus a court mandated service project in a multi-ethnic environment
Rehabilitation - when the above is satisfied, back to the match if he wants, hopefully a changed man
I'm slightly uncomfortable with an overemphasis on the punishment aspect if it stymies the other two things needed.