Supposition is defined as an uncertain belief. Therefore, there not being a reason for things or a why would be just as much of a supposition as if I were to say that there is.
There being no why or reason for things is worthy of the same amount of burden of evidence/explanation for if I were to say the opposite. And to say there isn't a reason or a why for things wouldn't/shouldn't make anything being a supposition not worthy of ones consideration just because anything born from an is or an isn't can be considered as supposition based off metaphysical assumptions.
So you're saying scientific theory is not worth the time and energy to even consider? Scientific theory being based off metaphysical assumptions. If so, you're saying The Big Bang wasn't worth not only the time and effort to think up in the first place, but not even worthy of anyone's consideration?
My point exactly.