I start by apologising if I have took sparse sentences to literally. If I didn't understand something that's is why I am asking.
In more or less divulgative literature, here, and also in the few cosmology books I went through so far, it appears as a wonder that universe is so homogeneous at a sufficiently large scale. This, together with the limit of the speed of light / information, prompts for questions such as "how can be that different and opposite sites of the observable universe have the same temperature" and the like. This, to me, would come to surprise if one assume a certain degree of pre-existing differentiation to be levelled out and smoothed.
I am puzzled because I would personally take the opposite view.
How it is that something that originates from the same event and from which everything tooks place differentiate in structures exceeding quantum fluctuation?
I am not asking for the answer to this question, but rather for why the observed homogeneity is presented as surprising and requiring a specific explanation.
Sentences such as "how could those parts of the universe knew of each others" are generally presented as obvious questions. But I don't see, perhaps naively, why things originated by the same big bang should be expected less homogeneous than what is observed.
I am otherwise fine with the current standard cosmology, I am missing the logic or the reason for which a specific explanation for the homogenous cosmic background radiation seems to be required. The history of each point in the universe should be the same, after all (except for fluctuations and the later formation of structures under gravitational influence).