Well, there's anthropic reasoning. Many equations in physics require the insertion of constants. The problem is that these constants have totally ad hoc and unexplainable values. And in many cases, such as the fine structure constant, a different value for the constant could produce a vastly different universe. So, why do we find ourselves in the one that allows life, however statistically unlikely it appears (from what we know)?
That's where the anthropic principle comes in. In it's weak form, it's trivially obvious - we live in a universe where life could evolve because if it didn't, we wouldn't be around to wonder why in the first place. But that doesn't explain anything.
However, in it's strong form, it states that every possible arrangement of values occurs somewhere, and we find ourselves in the place where they have the right values that life can evolve. One example where the anthropic principle is very successful is it's application to why Earth had just the right conditions to allow for evolution. Well, it's because there is so many planets in the galaxy, that somewhere must have the right properties.
Applying it to the constants of the universe is much more difficult, because there isn't an 'anthropic landscape' that appears to allow for constants to vary in the first place. Unless, you postulate a multiverse. This is where it becomes controversial - as does anything discussing a multiverse. One type that has become somewhat popular is the string landscape. One scenario of inflation, eternal inflation, allows for the production of a multiverse - slowly expanding regions where inflation has ended are separated by a rapidly expanding inflating region. Combined with string theory, which allows a whopping 10500 different vacuum solutions, the different inflationary pocket universes can have different constants.
But here's the catch - falsifiability. Eternal inflation does make predictions regarding the CMB, so it is testable. But we have no way of knowing if they don't exist if we don't see these predictions, since supporters can just claim these other universes never had an effect on ours.
Even if we found out eternal inflation was true, we'd still have no way of knowing whether the pocket universes were different from ours, since string theory isn't testable.