You have the anthropic principle: you can only observe a universe that produces observers. More specifically, if a universe existed that is full of dispersed hy

You have the anthropic principle: you can only observe a universe that produces observers. More specifically, if a universe existed that is full of dispersed hydrogen, we wouldn't be there to observe it. The universe must be fine tuned in some way, not just the constants but the very laws of physics. But this is an undecidable and therefore unscientific problem. The reason scientists want our universe to be "typical" is that the more we can generalize our findings, the more we can make predictions. For example if we can find an equation that gives us the cosmological constant exactly, we can get rid of it as a free parameter. Not only it is philosophically satisfying, but we may also use that equation to find something else, like a new particle, maybe even a practical application.