Well, according to the definition, my trike counts as "vintage". But in fact, they still make nearly the identical model 23-38 years later, and you can still buy new parts for it from the manufacturer. And it's still useable. So there's a nice long post on it, only it isn't in the C&V section, it's in the Utility Forum.

Realistically, the content of the C&V forum is VERY skewed to a certain type and era of bicycle. 95% of it is multi-speed bikes from the 70's and 80's. You'll see the occasional old cruiser post, but considering that the Schwinn cruisers probably outsold Worksman bikes 100 to 1 or more, it's not too surprising not to see them too often.

As I pointed out above, I have seen posts on old Worksman bikes, just not on THIS forum- but rather on forums that dealt more specifically with "old" bikes and not 70's/80's 10-speeds. I've never heard of the frame of a Worksman bike "wearing out", and pretty much everything else is replaceable. So there is no inherent reason why bikes as old as the hills wouldn't still be floating around. I would expect that industrial use and corporate ownership would account for the low numbers you see.

I think you'll find a similar thing in the automotive world. When I was in high school and college, I worked at a dump truck place that mainly ran old Internationals. These were gas-engine 18-wheelers or 10-wheel bobtails, mostly with straight 6's, the hoods that folded up in the middle, etc. I think they were from the early 60's, but pretty much looked like trucks from the 40's. But, you just don't hardly see any of those around now, especially restored to "new". And for every one you see, you'll see 10,000 hot rods and restored cars from the same era. Heavy use just drove those things right into the ground, and corporate ownership sent most of them to the scrap yard instead of somebody's barn. But it's not a reflection on the trucks that you don't see many around now. In a similar way, you see lots and lots of old tractors, but very few old bulldozers.