Personally, I am a collector of many things - as many of us are. Bottles, coins, advertising art, porcelain signs, movie posters, tin litho and cast-iron toys, rare books are things that interest me (and muscle cars), but bikes bit me the hardest. I started collecting and building in 1980 and sorta got out of bikes in the mid '90s, but still kept some basket cases for later. Later is now for me and I see a flurry of activity here on the CABE, but there used to be so many shows and swap meets in Orange County, there are a few now which is a good sign - but nothing like it was. We all like Ballooners and the Safety, and TOC's because they have style, and were just built better (like everything else before 1950). That style will never go away.
I just dug out an old copy of Classic Bicycle and Whizzer News by Leo Dixon, where he said in the '70's he would ride up on a balloon tire bike and other bike collectors would say "get that thing outa here". It wasn't that long ago when prewar bikes were only as old as the early BMX bikes are today. There are phases, and I haven't been active for many years to really tell if there is a slow-down in this hobby, 'cause it' speeding up for me. I think bikes will always be pretty solid, they don't cost as much or take up as much space as a collectible car, it's a hobby where you can own something really nice for less than $1,500.00, and find something that is historically significant for around $4,000.00, you can't get many collectible car parts for that. I guess the hobby really started dying and yet was invigorated at the same time when Schwinn filed for bankruptcy in '92 and ended up selling it's collection, releasing many bikes into the hands of hungry collectors.