I have nothing against folders, but I am happy with shelves/collections on all of my readers except Kobo.
I probably wouldn't use folders much on a reader because it is touch screen with a small screen, and basically a single use device for me. And I don't want to have to type stuff in on a touch screen unless I have too
Still it should not be a big deal for one of the companies like Sony or Amazon to incorporate an experimental file browser or build it into the web browser and you will hear no squawks from me if they do unless they took away collections.
BTW my tablet does not have a real built in file browser either. I have a 3rd party one on it which I seldom use, but it is nice to know I have it if I need it of course. But I don't actually need it AFAIK.
I understand that those who have grown accustomed to one way of organising their books, cumbersome or not are reluctant to abandon something that they have been doing for years and years, but as a person who started out on CPM and Unix, I have long ago learned that being set in my ways is not going to convince anyone that my way is the best way, and just puts me behind the times.
Still the programming required to put in a file browser is not rocket science and would have no real detrimental effect except to allow more user error, but we are used to that
Still the major ereader developers seem adamant in their refusal to do this, so I don't see it happening this year anyway. (famous last words)
Helen