I've never understood why people compare complete careers, or the stats from people who are older and further along in their development, to that of younger players.
(not saying you are doing this, at least I don't think you are).
Sometimes players take longer to develop then people think. Look at Steve Nash. He didn't average double figures until he was 26, and in his 5th season. Tyson Chandler didn't really come into his own until he was about 23-25.
Many players would've been given up and cast aside early in their careers in the eyes of many fans.