There's bound to be drama surrounding this kind of topic anyway, because stuff is getting so ridiculous. There's a lot of reasons why a hobby like this might 'die down'. If you couldn't tell, we're about all sick of the ridiculosity of vintage PS3s and shovelware NES titles fetching a small fortune, opportunist sellers with lazy methods and poor service, and the overall floodgate of late comers making competition for scraps quite fierce.
If things are dying down it is not because its gotten stale, or because it's not a cool thing to do anymore. If it's not as fun anymore, its because it has been made that way as of the past several years it seems.