That might be how the media portrays payment gateways such as Paypal, and to an extent, you'd be right - But there are laws to obide by, and trust me when I say that adult sites (doesn't have to be pornographic, just adult) are heavily scrutinized. If you want to create a website that accepts VISA or MASTERCARDs etc, you have to go through quite a lot of loops and sign a number of documents. It's not as easy as installing a plugin on your website and clicking 'install'. It's even harder for adult sites.
And yes, AllGravure would be considered an adult site by nearly all global payment processors. You can't use Paypal or 2Checkout with a site like this, they won't go anywhere near it.