Oh yeah, I forgot to reiterate none of their actions are removing any books from the public domain, and as such are completely acceptable.
It is 100% acceptable to use content that is in public domain for commercial purposes. You want to make a movie? Write an opera? Charge $15 admission for the movie you made, or $750 for admission to said opera? Totally legit. Yes, that absolutely includes
modifying the content and adding DRM, if you so choose.
"Public domain" is a set of laws regulating content, and that's about it. Any sort of "cultural conscience" is of your own invention and, as such, is (to put it mildly) non-binding.