Cause these kids want to play pro ball and the only ball they imitate is pro ball.
Lakers
Celtics
Bucks
Heat
Nets
Warriors (when healthy)
Raptors
Mavs
Nuggets
Blazers
Suns
Its all about the three ball baby.
Look at this box score from two bad NBA teams two days ago
https://www.espn.com/nba/boxscore?gameId=401267371
Both team shot half their shots (or close enough) from three and without a shot chart not many midrange shots would be an accurate guess.