The theist's fine tuning argument is so wrong that it's actually a good argument for strong atheism. In fact, the opposite argument would be more indicative for theism. For example, if we with our frail carbon-based bodies survived impossibly in a hostile environment with acid rain, a toxic atmosphere, and molten lava knee-deep, on a planet that miraculously existed in a universe where the laws of physics do not permit the formation of planets, then you might have a case for the supernatural.
But we're here instead. We are here, on the one planet that can support us naturally. We are here, in the one universe that does allow for our existence. We are here, in the only place in the known universe where we can possibly survive without supernatural support, because we couldn't be anywhere else without help from a god.