That chaotic short spell I served in a bike shop had me dealing with all the 'old stuff'
Bleeding obscure disc brakes as nobody else seemed to able to do/ be bothered as it didnt had Avid or Hope written on it.
And fitting a Rollamajig to a tandem as the previous effort had made a complete arse of it - that 'effort' complaining that it was old and designed badly - despite the fact the tandem was about 6 months old and was running Ultegra (hence the need for some sort of translation from the canti pull of the Sti to the V-brake).
The current market shouts discs and road bikes so thats what the yoof are concentrating on. Cantilevers only appear on the cheap and on the rare sale of a cyclocross bike.
Doods like us that have a wider experience/ span over the years are a rare breed so cannot expect others to be as aware of obscure old tat as we are.
Unless you subscribe to MBR and buy the latest kit every six months following the shrinking herd who believe every word written (''...that 1 degree headtube change really brought the trails alive...''), you'll be deleted from the yoofs brain within a week.
I've encountered open hostility in some bike shops and out on the trails when riding something obscure which has left me quite upset at the time. All it has served to do is to think a big 'F


k off' to the 'all the gear, dont give a F


k about others on the trails' types and straight to the internet for parts.
And that was 2006!