I don't see any problem, frankly. I may watch occasional hentai out of boredom, but I'm not a huge fan of it. In fact, to me a lot of it is rather just plain sick. I don't condemn anyone, this is just my own feelings towards it. if it all goes away, so what? You can find hentai and porn anywheres online as well as at any adult bookstore. You can buy adult comics and Heavy Metal magazine almost anywhere too.
This sounds more like a bunch of leeches complaining. If you have been a member but never post, if you aren't sharing anything or contributing anything, If you don't post in any discussion threads or anything else...well, honestly what good are you? A "member" who ONLY downloads isn't much of a member. Had plenty of those on one of my old sites. People that like to get the "latest fix" so they could watch tv, but couldn't be bothered to say thank-you, or be productive members of our little "society"....but just let ONE THING be taken away from them, and they raised holy hell!
RJ and Wolf are correct. There are other places to view or download Hentai, I'm a member of a couple, myself! And I'm sure those sites would love to have you as well, as long as you intend to be a productive member! You need to remember- courtesy is a TWO-WAY street! If you are a bit more active, and make friends with people, I'm certain they will be more than happy to direct you to some nice Hentai sites you can freely join. Also, Google and other search engines still work nicely for finding content if you know how to search and have a good antivirus program and firewall!
Finally- don't forget that a lot of sites that have any form of adult content not only come under fire legally, but also get hacked, taken down, attacked, etc. and some are also "malicious" sites, with viruses that hit you just for surfing to the page... so, is it REALLY that important you get your daily cartoon fetish? If so, get active and make some friends...you'll find the decent sites a lot faster that way!
We're a happy community here, so we help out our friends! ;)