In my opinion I think it's generally the hipster crowd latching on to a new cool. It happens to every sub-culture. Obviously there is a limit to the supply of old things but I think you will find that once the new shiny cool of vintage old stuff dissipates the crowd move on and guys like Magnus are still there decades later doing their thing.

The custom motorcycle scene is a good example of this. So much new stuff flooded the market and everyone, including the new guys got bored. The shift to the old vintage and "garage" built stuff became the new hotness and now the old guard are having to pay stupidly high prices for half a cracked case and two burnt out pistons.

New comers with money buy up everything. Eventually though, either they don't have a clue what they are doing and/or give up soon after and just store the shit with the other failed quarter/mid life crisis dreams.

Like you though, it might be sour grapes.