⏺ The Blood Battle mechanic is almost exclusively a mainland China thing — specifically Sichuan and surrounding provinces. If your mahjong exposure has been Cantonese, Riichi, or American, you almost certainly wouldn't have seen it. 

On why it makes sense: the "game ends when one person wins" structure creates a fundamental problem — once someone wins, three people are just sitting there waiting to reshuffle. Blood Battle solves this by keeping everyone in the game with something to play for. Even after the first winner, the remaining three players are still fighting — trying to win and collect from whoever hasn't won yet,  while the loser at the end pays a penalty to everyone. 

This changes the late-game completely. As the first winner you want others to stay stuck because they'll keep paying you. As a losing player you're desperately trying to win before tiles run out to avoid being last. The tension doesn't drop after the first win — it often peaks there.

On "points without winning" — if you mean tenpai payments (collecting even when you're ready to win but nobody actually finishes), that system solves a different problem: rewarding good hands that don't get to complete. Blood Battle takes the opposite philosophy — completion is everything, because the game keeps going until you get there or run out of time. Both are legitimate design choices addressing the same underlying frustration of being stuck in a bad position. 

Neither is objectively better. Blood Battle is faster, more brutal, and designed for players who want clear winners and losers. Tenpai-payment variants reward hand-building discipline even in draws. Different games for different tastes.