Apple's only moral responsibility is to let their users do whatever they feel like, and they have failed.
No. It isn't. Their moral responsibility is to maximize shareholder profits which they have succeeded in doing, beyond expectations. They have decided to not appeal to fringe geeks and nerds but to instead appeal to the affluent mass market in order to meet their moral responsibility. That moral mass market would prefer if "porn" was not readily available on their consumer electronic devices. _YOU_ may not like that but Apple's shareholders, to whom Apple answers, likes it quite a bit.
They have a legal responsibility to maximize shareholder profits, not a moral one.
The number of UNIX installations has grown to 10, with more expected. -- The Unix Programmer's Manual, 2nd Edition, June 1972