JAV has better girls, better action, better cinematography, better production values than western porn - JAVs evidently have a lot more money flowing into them to pay for all these things. So to suggest that JAVs need to cater to the west to get more money seems strange to me, especially considering that the porn industry in the west is dying, if not already dead.
Amateurs are destroying the porn industry in the west and I think that says all that needs to be said about the low quality of "professional" western porn. JAV is just superior, despite being censored, or perhaps partly because they have to compensate for censorship. Take away one unique aspect of JAV, and you might take away other unique aspects of JAV too. JAV is JAV, I think it's better to just accept that, or just watch go western porn instead.