Trek Y… I really wanted one of them back in the day!
As for where they all go, haven't you ever seen an old person on a really nice bike? They get left in sheds when kids go off to uni, they get put in the back of garages, they get left at mates houses for a long time. they're everywhere!
There's an old guy round our way who rides a fully mud guarded, pannierd (spelling?) orange clockwork with all XT bits… There was an old P7 in the garage at work last year that someone had "borrowed off a mate." the lad who lived across from me last year had a saracen type bike, with chris king headset and XTR Hubs… stuff just gets passed around, frames break and things get forgotten!