I think Rak flashed better than expected offensive potential as a frosh but he never came close to realizing it until he was a senior when everything seemed to happen all at once. I mean, if we're going by FG percentage, Billy Celuk was at 57.7 in 2000/01 and Jeremy McNeil was at 65%. If we look at PPG, he was around 5-6 ppg both his soph and jr seasons which is less than what Roberson averaged and it wasn't like we were featuring Roberson nor was it that he was a particularly effective offensive player.
Now, there is no question that we didn't feed Rak -- and arguably little question that we would have been better served by at least making the effort to get him a few more touches if for no reason other than to allow him to work on that part of his game. But Rak had trouble putting himself in good spots offensively and often when he had good position he got pushed off of it. There was also the massive issue of foul trouble and playing well enough on both ends to keep himself on the floor (over 100 fouls in ~800 minutes in each of his soph and jr seasons).
Anyway, to say he could have scored more earlier in his career is probably fair, but to say it's mythology that he appeared largely out of nowhere as a go-to guy as a senior is absolutely accurate. Even we love a player's potential (like MCW going into his soph season after an impressive frosh season in limited minutes), to go from ~ 5.8 ppg and 5 rpg to 17.5 ppg and 9 rpg while still sporting a really good shooting percentage (55% in Rak's case) is absolutely insane in terms of the jump in productivity. I think of guys who had huge leaps from one season to the next and I can't really come up with a good comp. Damone Brown was great as a senior but had averaged 10 and 6 as a junior. Rick Jackson stepped up but had been at 10 and 7 as a junior. MCW might be the closest in terms of raw numbers but his lack of numbers as a frosh had more to do with lack of opportunity to get on the court.