I don't know about other leagues, but as far as I know in the NBA, when the game is in garbage time, both teams actually empty the bench to let their subs/reserves play.
In BB however, only the winning team does that. I've actually seen blowout games turned into close games because of this, and also if the losing team is coincidentally playing patient, their main shooter can actually stat pad by hitting more than half of their points total if the gap is big enough and garbage time starts in the third quarter (I've came across this pretty often) coz they're shooting over an inferior player who is not allowed to take a break for the rest of the game.
I understand the fact that this is done to "help out the weaker teams", but if both teams empty the bench, their players still has enough space in their weekly minutes to contribute in the cup, where they get extra money for winning. I mean, who won't love to play their starters in all 3 games of the week and still have good game shape? Why force them to eat up their player's minutes by pushing in an already meaningless game?