Yes its harder because you need another two players for it. If you dont grush, you just play the game and not need anyone. Easier.
There is no valid reason why fix this. It doest affect you anyhow. There is really nothing to fix anyway. People call it glitch but its really not because its how quests in D2 works online. You finish them even standing in town while others do it. All quests with exception of horadric malus and ancients. Which were limited to avoid xp gain abuse from reward.
There is not any glitch with baal. With exception of quest bug for loot.