I can understand the principle here. Just to confirm, though, you'd then have no problems with controversial books being donated by private groups to public libraries, is that right? Or are there other considerations in your calculus.
Wait, but both of those are censorship of a form; Apple is just allowed to censor whatever it wants.
Taken to the extreme, should a library be allowed to stock only books that promote the political party of whoever won the latest election?
Obviously decisions for shelf space have to be made. If those decisions for shelf space are made solely by the government's dislike of the material, though, that feels pretty obviously like government censorship to me.