It is a knock on the guy, and it is not true. Robinson has long arms and good ups, which is a part of athleticism but not the whole story. I have long arms and had decent ups in college and I am a terrible athlete, even by middle aged YMCA pickup game standards.
Robinson worked very hard on his game at UConn, and developed solid low post moves and a nice fadeaway. He worked hard on his outside shot, and became a decent 3 point shooter his final season. He shot over 50% from the field two seasons in a row, which indicates a smart player with good shot selection, and in 09-10 he had 79 3 point shot attempts, which makes his 52.5% from the field even more impressive. He even averaged at least an assist a game his last 3 years, which is solid for someone playing at both the 3 and the 4 position in Calhoun's offense.
He was not as fast as some of the top forwards in the league from that era, like Wesley Johnson, or have as good body control as Jimmy Butler, Greg Monroe or Samardo Samuels, but he held his own against those future NBA players most of the time.
Sticks was a good player that busted his butt to get better, and it is kind of insulting to him to say he was just an unskilled athlete.