Mouthwash, in this case I not only completely agree with
Watsisname in what he said but I would like to point out that answering you question may imply that laws of nature are something that nature has in it and not a consequence of the act of observing it and describing its behaviour with mathematical rules.
Besides that I would like to expand something:
The only alternatives are that (A) some higher entity created/simulated our universe or (B) there are enough universes that at least some of them get all the values within a range that allows it to contain observers.
Maybe A is the correct explanation. Maybe B is. Maybe it's neither. Maybe God did it. Maybe it's a coincidence.
1)
There are not only two possibilities at all. Some mechanism could be involved in the fine-tunning of those universal parameters but that doesn't mean that the only mechanism possible is an intelligent superior being doing it because he want life in his universe. Why should he wanted to do in that way anyway? maybe also a superior being could want to do a universe without life and having much more complex phenomena. Why the intelligent being that simulated reality wanted it like this? It looks like he is the fine-tunned one because is, as an intelligence, particularly fine for us to exist. You just displaced the problem. Why no other mechanism is possible? Top-down cosmology for example, etc...
I mean. That was also part of the argument about life before Darwinian Theory. How perfect and suitable is the world around us to us to live in it. The air is fresh, the water can be drinked and is abundant, the sun shines and the mass of earth is the best so our bones don't degrade so much nor they get crushed by gravity. Such a perfect place. Who chosed it? No one. The thing is that life has evolved to be in concordance with the environment. The same can be said about this. Yeah those physical parameters are near perfect for us to be here but 1) The Universe is not fine-tuned to life; life is fine-tuned to the Universe it has evolved in and 2) "If the universe was designed for life, it must be said that it is a shockingly inefficient design. There are vast reaches of the universe in which life as we know it is clearly impossible: gravitational forces would be crushing, or radiation levels are too high for complex molecules to exist, or temperatures would make the formation of stable chemical bonds impossible" as Robert L. Park says.
This is very very important. Besides jokes, the universal constants are suited for life but only in the most exquisite parts of it. Life can't arise in stars, not in cold places (because of complex chemical reactions been impossible in those environments), not in objects with huge gravity, nor in objects with high doses of radiation. And that without mentioning that life can't arise or thrive in empty space (the vast majority of what there is in the universe). So yeah the universe is suited for life, but only in this tiny little patches and only during a very short time period (could life develop when the universe becomes black hole zoo without stars? could live develop when thermal equilibrium is reached? could have developed when this was a elementary particles plasma soup?). Maybe if the universal laws and constants were different then life could arise on much more places, maybe some rules allow space-time to behave in a self conscious complex dynamical way and entire light years of space are living and thinking instead of just a small dust particle suspended in a sunbeam in the void.
2) Why you even need a mechanism to explain we are here? This has to do with the anthropic principle, I mean you wouldn't be able to ask that question if you weren't here in the first place so what sense does thinking the universe is fine-tunned for you make?
You don't need other universes to explain this. Even if this is the only universe you still exist and therefore the probability is still 100% sure life is compatible with this context even if this context was nearly impossible. If we have a winning loto that doesn't mean that we have tried many, maybe just one was saled. But the difference here is that you would exist and ask this question only if the wining loto was the one that was saled.
Another thing is the fact that you seem to be very confident with the idea of the impossibility of other life forms and physical structures as complex as ours arising from another set of natural laws. If the universe had other rules that would allow for other life forms then they would think exactly the same as you. You are interpreting that only one kind of life could have the right to be and as a consequence that only one kind of parameters are suited for life ignoring all the possible values where the universe would be suited for it (even better than our current parameters).
Also there's a very important point.
Not only there are other parameters that can give rise to other kind of processes that give birth to lifeformsthat could ask your same questions, but also is not true that changing a bit the current physical constants life would be impossible. The range is much wider than we usually think and we are starting to understand that now. And this is expected. Think about it; we know that life needs for chemical reactions to occur, we know that for many of those chemical reactions to occur you need electromagnetism to be very strong as to have electrons around atoms and also weak in some sense (in such a way that the nucleus of atoms don't explode because of the repulsion between protons). So since we know that, following that path we conclude that the value that describe the intensity of electromagnetic forces is quite perfect for us coincidentally. What is missing? If you didn't know life existed on this universe and you where given the laws of nature do you really think you could predict the existence of life as a consequence? I mean we are still unable to explain how can it be since we still don't know how it formed how can you predict the complexity of geologic processes, chemistry, nuclear reactions or life if I gave you another set of rules? You would have to make a lot a lot of work, more than its currently possible, in essence you would have to simulate the universe to see if this happens. Sure, there are many possibilities where you would not expect life to arise but would you have expected it in our universe? in this violent and quiet at the same time, expanding void with some impurities floating on it?