This is it.
First editions in many other art fields command the highest prices be that fine art prints, ceramics, first edition books etc. Why should recorded music be any different?
If people want to pay to own the "original" in pristine condition and they can afford to do so then so be it and good luck to them, it's their money.
I'd hazard a guess that some of them do play the LPs rather than hang them on the wall but even if they don't and only keep them as an artefact I can't get upset about that either. It's a lovely thing to own.
Some of these collectors may equally regard having at least two box sets containing the same version of the album on the same format as a bit odd, after all you can only play one at a time.