Porn is exploitative under capitalism because it's capitalism. I do think, however, that drawing arbitrary lines to keep eroticism private while socializing every other aspect of human life is, in fact, arbitrary and not rooted in any Marxist understanding. Communism will also orient eroticism, just like every other factor of human life, outwards, not inwards.

If you think the war on drugs was a failure, just wait till you see what your idea would cause.