I don't think players should have to acknowledge a pass move. It'd speed things up quite a bit if I could just make 8 (or however many) moves in a row without having to wait for my opponent to acknowledge the pass. Some players make 1 move per day, and there's nothing wrong with that, but you can imagine the frustration when it's a tournament game and everyone's waiting for one player to acknowledge the pass moves once a day. I'm not experiencing this right now, but it's happened quite a bit in the past.