If you watch the coverage that the networks provide the tournament, whether it is CBS, TBS, etc. it is obvious that Barkley is there to give opinions that stir the pot. By watching him for just a few minutes, you can be reasonably confident that he doesn't follow college basketball at all during the season and is just brought in at the end for the tournament. There are several times when he starts talking about a match up you can just tell he doesn't know anything about one or both teams, often cannot recall the names of the players on the team or just speaks in real general terms about teams that could be accurate descriptions of any team in the tournament (i.e. "they play hard" "they score a lot of points").
He spends the whole season doing pro basketball and then they bring him over for three weeks during the tournament for college basketball. Not sure why he and Kenny Smith are brought in, but they are both better to listen to than Gotlieb and Billy Packer when he was still there, so I don't complain too much.