There *are* interpretations of quantum mechanics which *do* explain the "meaning" of the equations. (I'm guessing that's what you mean by "why".) Unfortunately there are several different interpretations that are consistent with the math. My favorite is the Everett-Graham-Wheeler multiworld model, but it's not the only alternative, and so far there seems to be no way to choose between them. But there are only a few interpretations, so most possible ideas of how things could work, and what it all means, are incorrect.
E.g., if you hypothesize that some god is running things, you need to presume that he's systematically interfering with the experiments (or that he just created the universe 3 seconds ago complete with all internal evidence of consistency). If you do, that is consistent with quantum theory. But it's not a very useful interpretation, as it doesn't allow you to make any predictions. Another useless theory is "When the universe happened to come into being, it was set with a series of values that specify everything that is ever going to happen down the the sub-atomic level from the first instant of existence until the final end. That can be made consistent. (Actually, that one is useful if you combine it with a theory that the simplest possible set of constraints was used.)
The multiworld hypothesis basically says that the universe splits with every quantum interaction, and you move forwards into all of the results with a probability density that reflects the probability of the quantum events involved. At the high level that we interact with things that translates into "an honest die has a 1/6 chance of coming up with a 6". So it's one of the useful interpretations. And the Copenhagen interpretation basically says "Shut up and calculate. No explanation is possible.". Most working physicists prefer the Copenhagen interpretation, because it makes things simpler (without changing the math). There are others. Look up "implicate order" for example.