I think you're missing a point that has already been made. The Mafia doesn't need to put on a show, lead people down false trails, and so on. There is no trail at the moment. There simply isn't one. And the lack of votes speaks to this. They can kill without leaving any evidence, and there's nothing that can be done about it. The Mafia has an advantage, and there's no need for them to take risks, expose themselves, or come up with something during the day. The town is defensively losing in the long run anyway. Isn't this obvious?
I won't even mention that there's no point in playing as the Mafia to win in a mediocre way, thanks to their own passivity and the town's passivity. Everyone traditionally wants a beautiful victory.