I think that more people would want to use them if they weren't so difficult to come by, or so obscenely over-priced in markets like ebay.
Well, that's the issue, isn't? There are probably still several million C64s out there, not yet matched up with the remaining people who could actually use them. Same with Amigas - although the number is probably more like tens of thousands of unused Amigas. They are sitting in lofts, garages, closets all over the world. Every year some get matched up with people who like this stuff, but it is probably easier for people to just put them out with the trash instead. There are a lot of people out there who still can't imagine that anyone would actually WANT to use an old computer.
If there was an easy way to magically match all these Amigas with the remaining Amiga users, then probably every person who wanted a real hardware Amiga could have several - and the value wouldn't be so inflated.
With the advent of electronics recycling laws, etc. many people probably think they are doing a good thing by bringing their ancient Amiga out of the garage to be stripped down and recycled.