When they were kids, my father and his friends did the same with baseball cards. They would chew the gum, and then put the 'worthless' baseball cards into their bicycle wheel spokes.
Who knows how many Mickey Mantle rookie cards they might have come across.
Point is, nobody can predict when a currently-worthless item might explode in value.
Ok so first directly to your point are some envelopes I found recently that my Grandma had with what would have been potentially valuable stamps from the 1960s when stamp collecting was in its heyday. What actually happened is that many people were excited by the unusual prices paid for stamps at the time and hoarded what they thought would be valuable stamps in the future. (it even hit pop culture: the 1963 movie Charade is about someone who smuggled millions of dollars on a sheet of paper of priceless stamps)
As a result, when I was pricing these recently, they were apparently collected by every other 1960s hobbyist and put in a shoebox. You combine that with the fad of stamp collecting waning and now the first-issue, day-1, limited-edition 55 year old stamp is put up for a few dollars (and usually doesn't sell even then), because every one of them were snatched up.
Second, here's two other of my near-million misses:
I was in an early talk in the bay with what eventually became YouTube.
It went like this "yeah that's fine but what about real player? They tried all this already. On demand video isn't a new idea. Just another flying car. I wish you luck."
Then there was the time I worked in Venice and there was this small company called snapchat and i was like "isn't this a busy and well established market already? Don't consumers have things like MMS, imo, and a myriad of other options?"
Who knows, maybe if I did join then my dismissive pessimism would have been instrumental in their failure on some alternative timeline.
I think the right analysis here is that both companies succeeded because the demographic of who could access the technology and for what purpose changed ... so the same idea in different hands did different things. It really opens up the analysis when considering these as essentially commodity startups.
