It's more like, right now we have two rather bad explanations for basic quantum mechanics. There is the "particles change when a human measures them" explanation, and there is the "there are many worlds and we can usually only observe one" explanation. They both explain the same set of formulas that have been verified many times by experiment. Depending on what you want to do with the theory, it may be more intuitive to use one formulation than the other. Hopefully at some point in the future it becomes obvious that one of the formulations lacks the explanatory power of the other, and then scientists can cohere on one.
You're thinking about it wrong. Start from Bell's theorem - it tells us we have to sacrifice locality or realism. MWI weasels out of it by making worlds be observer dependent, basically splitting the observer up. Bell's theorem is the root. It's not an interpretation & all interpretations come from it.
Like epicycles as a scientific explanation of how the sun revolves around the earth. Somewhat off topic but interesting reading - http://en.wikipedia.org/wiki/Deferent_and_epicycle