I don't have the causality backwards. We don't have a complete knowledge of the laws of physics, and we have something which is unexplained. Whenever this was the case in the past, better laws were found which closed the explanatory gap. Why should it be any different this time?
The point of the anthropic principle isn't to explain it, it's to point out that an explanation is not required.
We could find that the laws of our universe are the only possible set of physical laws. This would be the expectation of the Newtonian era. In that case there is nothing to explain. Or it may be, and currently seems likely, that there are many possible sets of physical laws. Then the question of why we happen to have one of the perhaps very few possible sets of physical laws that allows intelligent life to develop seems to require an explanation. The anthropic principle explains why it really doesn't, because in the (possible or actual) universes where intelligent life is impossible, the question simply doesn't come up.
The point of the anthropic principle is precisely that we shouldn't expect to close the explanatory gap, because there isn't one. We shouldn't be surprised if physical laws seem to be "tuned" to allow intelligent life to emerge.
Imagine that planets orbited in randomly selected geometric shapes, and we happened to be on the only known elliptical one, giving us the conditions required for life. Would this lucky fact require explanation?
>Imagine that planets orbited in randomly selected geometric shapes, and we happened to be on the only known elliptical one, giving us the conditions required for life. Would this lucky fact require explanation?
No more than the existence of a planet of the right size at the right distance from the sun. You still have physical laws which determine what's possible, but they probably won't (and, in fact, don't) provide a complete explanation.
The weakest form of the Anthropic Principle is uncontroversial. For example, we can use it to conclude that physical laws which don't permit intelligent life to evolve must be wrong. Can we use it to rule out physical laws which don't entail the evolution of intelligent life? I would argue yes, but that doesn't require any fine-tuning of dimensionless constants: an infinite (e.g. Einstein-de Sitter) universe, or Everett's Many Worlds interpretation of quantum mechanics would entail it, given its possibility.
The anthropic principle is not about intelligent life determining the laws of physics. There is no magic there. You have the causality backwards.