Or at least let us choose.
As someone who isn't American (or a matter of fact being Asian and growing up in a competitive environment) I actually dislike garbage time. I know it's a cultural thing in American sports where you're supposed to respect your opponent and not humiliate them further, and that this game is somewhat modeled after the NBA so that's why we have it. But on the other hand, the rest of the world can't really relate to it (Goran Dragic definitely didn't bother about it in 2018 and Ben Simmons even agreed to his actions by saying he would have dunked it if it was him).
That said if we view this objectively:
1. Point difference is used as the tie breaker in the standings. Having garbage time prevents your team from competing fairly to extend your point difference by pitting your subs against your opponent's starters. I have games where I literally lead by 20 per quarter (up to 60-70 before the fourth) and my opponents just chip off the lead in the 4th because my subs played the end of the third plus the whole of the fourth.
2. Training and game shape are minute based. Garbage time really messes up with training and game shape minutes. Also in real life, coaches use garbage time to let role players have more play time, which they can improve from. Such a concept cannot happen in BB because if the players are outside of training position, they won't receive anything other than experience, and experience is useless as long as you don't have the skills (for the record, I have a 22 experience player and his performance is just comparable to another player of similar skill level who has 3 experience), so even the more reason to not have garbage time.
3. While meaningless, some people like their players on the leaderboards. Having a blowout game would literally mess with their PPG record.
There's literally no merit in having garbage time in this game, and it in fact doesn't complement the game design at all. So I don't see why it can't be removed.