Whilst that’s partly true Jim, if we look back further in time, we do not see interest in bikes die out when their original generation do. Veteran and pre war machines continue to generate interest and enjoy strong markets and prices.
I didn’t start riding until 1984, so I’m not one of the original generation myself, and there are younger followers than me.
I think bikes go through phases. Firstly the new phase. Then the ‘cheap old bike’ phase. Then the nostalgia driven ‘classic’ phase (this is the market driven by the original generation). Then there is the classic / collector phase where the bikes appeal to a different market, people who weren’t buying, or maybe weren’t born, when the bikes were current.