Some West Ham fans have been saying Arthur Masuaku should be sacked, which is a little over the top. Spitting is horrible and he was incredibly stupid to do it. But it was out of character and he has apologised. Masuaku will suffer a six-match suspension and a club fine and will then have to earn his place back and the trust of the coaching staff. That seems like punishment enough. He seems to be quite a laid back character and has never been sent off before, so it's not a recurring problem.
To put it in perspective, although spitting is reprehensible it's still not as bad as a leg-breaking tackle. Cardiff's Joe Bennett received a yellow card for a foul that put Man City's Sane out of the game for a month, while Masuaka has a red card and a six-game suspension. Luis Suarez is now a hero at Barcelona despite serial biting. Arthur's done wrong and been punished severely, which is surely enough.