I think it's only logical the porn industry (as well as games) will go this way, but not sure what this has to do with bitcoins?
bitcoin porn and games are very well tied together, did you read the last news about Backpage.com going full bitcoin because visa and mastercard were denying their support?
for example bitcoin can help those that want to subscribe with more privacy, in those porn sites
I think the real issue is why is porn available to the masses free for the most part?
because no one can prevent torrent, in the same they can't prevent bitcoin