I already gave a perfectly plausible explanation as to why they do not show low levels higher tier kit. It was then met with a wall of "yeah but if I did this" and frankly, that gets silly fast so I made that post to draw a line under it.
There ARE far bigger immersion issues than vendors, don't complain about little easily overlooked things when there are other things completely beyond explanation.
In summary, I offered a perfectly plausible in character solution/explanation to the issue, this was not good enough for some - my feeling is that if you're THAT hung up on 'realism' that you'll argue theoretical "yeah but my character would then...." ...pick something less realistic to complain about first.
The perfectly plausible explanation is that they chose to grade vendor gear in levels so that nobody could become too powerful, or excel too early. What you didn't give a reason for was why this was the best execution of that idea. Similarly, this is not a realism issue, this is the fact that progression through the game world feels very player tailored, which dulls any sort of ambition when dealing in mercantile, and also puts a great big question mark over the existence of the speechcraft tree. Many of the complaints here state that if the price had been raised on more powerful items, players would have some financial decisions to make. It's a fairly elegant solution to a problem widely voiced. What I don't understand, is what effect this change would have on you. For those of us who care, it's a fantastic change. For those who don't, like you, what does it matter? Or are you arguing that because you don't care, nobody should?
FYI, when we say we want static vendors, it means that or two vendors in the entire land would carry one or two ebony pieces, and some vendors would only carry Iron or Steel for the whole game (such as the guy in Riverwood). We don't mean a giant list of items that span the entire game all with every merchant.