This is a pretty interesting situation.
The facts I gathered is that while the site was legal concerning KDP authors who signed up for the 70% plan through KDP, the site culled ALL books from Amazon through an API.
Only problem with that is that some of the books are in Select or the 35% plan and they can opt out of lending, so by culling ALL books, some books that are not set up for lending were listed.
Seems like a lot of the authors are uninformed of not only the lending program but how it works. I think a lot of them thought that their books could be lent an unlimited amount of times, when books lent can only go out once in its lifetime.
In that light, I can see how some of the authors flipped out and they started the witch hunt. Doesn't forgive them for not knowing the agreement they signed, but I sort of see where they are coming from ... well some of them at least.