Twenty years on seems to be the peak of the rose tinted spectacles gap - that is, everything was better 20yrs ago (and always was). So maybe people are buying them because modern stuff is uninspiring, over regulated, too expensive etc and harking back to simpler times is a response. Plus, I suspect we all have our 'settle into a groove' period where we're on top of the bike market, know everything about what's available, what's best for travelling or whatever you want to do with it. Then things change and some years on you've no idea about who's producing what or if it's any good (unless you're in the industry). The bikes you knew are still perfectly functional - if you can find a good one - so why not.

The increase in emission zones is an interesting one and may well play a greater role in the future but for the moment there's a great deal of lip service being paid to them but (with the possible exception of London where there's so many cameras there's hardly any room for traffic) many of them are not that rigidly enforced (in my experience - ymmv). Even in London there's exemptions for vehicles registered as 'historic' which is why my old two strokes can 'healthily' blot out the centre of the city with smoke but my 20yr old Land Rover gets (got) me a £200 fine. The L.R. will be up for sale in the New Year but I don't suppose I'll be getting too many enquiries from the London area.