Pogba received a series of racist messages on Twitter after his penalty was saved by Rui Patricio in the 1-1 draw at Molineux.
"It's not something we should be speaking about, because it should have been eradicated a long time ago," Mata said in an exclusive interview with ESPN.
"That's one of the things about social media. It's fantastic to connect people if you use it for the right things.
"But it also gives a chance for so many people to let go of their frustrations towards other people and with no problems because there are so many fake accounts. There's no identity. Then you can say whatever you want and you are not punished.
"It's a problem. Unfortunately some people do that and it needs to stop. It's cowardly to do it that way because no one can see you. It's not nice."