Is there really any problem with an infinate regresion of universes?

[Mudhammam]

Still, it's reasonable to ask why it didn't remain hot, dense, and very small, and to term the conditions that resulted in the expansion of the Universe we perceive as the beginning of spacetime existence, no? 

Of course, ask away. But you cannot use the known physical laws to something about that state when the known physical laws don't work in that regime.

I agree... yet isn't there a threshold to the amount of head-exploding that a notion, such as an uncaused beginning (or a becoming of a current state), is allowed before we say, "Okay, that obviously isn't correct." I mean, I've come to expect science to defy intuition but formal logic? It seems like a dangerous line to tow less we just start accepting explanations because they're all that we have, even if they aren't that good. What do you think?