HAHAHAHAHAHAHAHAHAHAHAHAHA
This really didn't need its own thread, especially since I touched on the answer in the original thread. Simplest explanation possible: I wasn't good enough.
The more nuanced explanation: I had one of the worst possible games for that level of basketball - I had a mean post game, great court vision, and could step out to hit 3s. In high school that made me a matchup problem; at a top level school that made me a player without a position. 6'6 isn't as tall as it seems to a lot of people, not when it comes to the upper levels of ball. At 6'6 you better have some elite perimeter skills, or play some monster D. I was never a good defender, only adequate because I had good length. Also, the difference between getting your shot off against high school comp and a top level athlete who is anywhere from 6'3 to 6'11... It's night and day. Against a regular dude I could hit 10 3s in a row, blow by him from the key for dunks, put the ball behind my back and crossover... against an elite level player? Shiiiiit... that first dribble better have a real purpose, or your cookies are getting taken, or you're getting pushed to a bad spot by the defender's quickness and anticipation. And that jumper needs to have a hair-trigger release or you're basically just a spot up shooter.
One of the best basketball players I ever saw was a 6'1 power forward on the D III level. Dude's athleticism was insane, his court vision was uncanny, and he played beast ass defense. But he was a 6'1 power forward. Handle at the D I level would've been shay as shyt, and the mechanics on his jumper were horrendous. But he had NBA level athleticism. Similarly, one of the best PGs I ever played with was a 5'7 white dude from the Appalachian Mountains... Word to my mother, son could get anywhere he wanted at anytime, best passer I ever saw, unguardable - I saw him frustrate an NBA-bound guard for 3 straight games, had him ready to fight. But he was a 5'7 point guard, and couldn't hit from 3 over anyone with height.
By the time I dedicated myself to bulking up, I got hurt in a freak incident on the court, and had to have surgery. And that was that.