Not a owner,but I would say for the ones that do it'd have to be SE looking at more weight to a index.html .
Wasteful I really don't see it,its just a dir 01 to whatever with afew jpegs and a index page.
I would say most do think that way its not like they get a ton of hits from having the recip,but they do weigh better in serp.
I could be wrong and more often then not am hahaha
