Except that it is easy to get the easy stuff completely wrong, in the case of the CMB. Part of your due dilligence in getting it right should include having a reasonable and responsible scenario that the easy things should work with. The current description of a universe that is homogeneous and isotropic works better as you increase the scale. One big bang seems like the large scale view to someone looking at our Hubble view, and then connecting everything in it and everything still out of sight from it to one singularity. The singularity says the Big Bang stands alone; doesn't need or even accept the possibility of before and beyond. I seems that it would be really easy to get your cosmology of the universe wrong. All you need is for there to be preconditions, like a greater universe composed of a landscape of big bang type events. How would that change the nature and source of the CMB? Wouldn't some hemispherical asymmetry in the CMB then have some new explanations? And would dark energy possibly have something to do with the accelarating expansion of one high energy density big bang arena, as its density equalizes with the supposed surrounding lower energy density space?