Yes there is a reason .... so many of the participants in collecting old bicycles are that desperate
to own one because it means prestige for their ego and money in their wallet, which means that many of those into collecting things are in it because of prestige and money, which is sort of sad. It is the same way for collectors of any material objects, cameras, motorcycles, automobiles, pocket-knives....
The other reason would be ignorance. For instance in the thread I started about my circa-1900 Pierce I wondered out-loud if it was a racing bicycle because it was a "fixie", because I was not educated enough to know that it was normal for bicycles in 1900 to be fixed-gear and that a coaster rear-hub was a luxury or extra-cost option.
So take your pick.....