When scientists speak of fine-tuned universes, they are referring to universes that are life-permitting. By life-permitting, they do not mean that life can exist wherever. By life-permitting, they do not mean that life can exist whenever. Furthermore, they do not even guarantee that life will exist. It’s a much more modest claim. It only holds that the fine-tuning will permit the existence of life. That’s it.
When scientists consider the landscape of possible universes, they have determined that they would be absolutely dominated by a wasteland of dead, boring, simple, lifeless universes. In my original article, I looked at what would happen if we changed the masses of the fundamental particles that make up everything made of matter: the up quark, the down quark, and the electron. Even minor changes to these values destroy the possibility of chemistry. Life has no chance in a universe with no chemistry, no galaxies, no stars, and no planets.
On the other hand, a fine-tuned universe, like ours, allows for the possibility of life. The fact that there can be life somewhere in a universe is precisely because the fundamental physics is finely tuned. Without this fine-tuning, there would be no life, anywhere, period.
It should be obvious by now that the fine-tuning argument holds in the relation to the universe as a whole, and is not meant to address the question of why you cannot live on the sun or breathe on the moon. Of course sources of energy (stars) are needed to drive life and evolution, and of course you cannot live on them. Nor can you live in the, by necessity, frighteningly large stretches of empty space between them and planets. So what is the point? Nobody would deny that the light bulb is an invention that greatly enhances modern life. But when you would try to hold your hand around a light bulb that is turned on, you would burn it to pieces. Is the light bulb then "hostile to life"? Certainly not. This modest example, however, indicates how utterly irrelevant the argument really is – one of those false arguments that appear to be brought forth and rehashed solely in order to avoid the deeper issues.