Do you really think so though? Which countries didn't have reliable internet that were actually purchasing legit copies of JAV? If anything I would be they were buying bootleg versions I know I have seen some while traveling.
Almost all of the JAV industry is in Japan and it certainly had piracy, and the speed back then. I just don't think it is a good argument, people still purchase JAV. The difference they are seeing in income imo, is from the fact that they were dominant at the emergence/booming of a market and now they have more competition so their market share is not as strong as it once was. Just simple supply and demand, and unaffected by piracy (since piracy is mostly from people who would not purchase, and the loss of purchases is likely offset by exposure leading to new customers). The same claims have been made by other entertainment industries. It is difficult to prove, and there certainly doesn't seem to be the creative crises they predicted, talent is still getting paid and still draws people in every entertainment industry including adult (JAV especially).
around the world
not only in JAV but mainstream movies and musics, while you traveling you did not notice a lot of legit stores out of bussiness ?
disagree with what I bold, piracy does affected and not difficult to prove, sorry to say this but people who said industry are unaffected by piracy usually are selfish hypocrite who won't accept the fact that piracy is wrong and don't care its can make other people close their bussiness, as long its not them that loosing profits