The biggest problem with those sites is that they embolden each other to abuse children. I know that they would do the same thing underground, but it wouldn't be as easy for someone who knows it's a problem, and is looking for help, to find them, and they might be more likely to go to a therapist instead of to a group of pedophiles for help.
Another problem with the sites is that young people who are confused about sex, etc, are finding these sites and are confusing being young and gay with being pedophilic. That's a big problem. Here's a good article that can explain this better than I can:
http://wikisposure.com/Indoctrination_Campaign
Yeah, I know, what's up with always quoting wikisposure. Well, it's THE one stop resource for online pedophile activism, and is very accurate.
I'm certainly not going to bash you, because you do have a point. The folks at wikisposure wouldn't have been able to find the vast amount of information about these people if these sites were illegal. However, if you take a look at the number of those people who have committed crimes in the past 13 or whatever years that they've been online emboldening each other, the picture becomes pretty clear. Many of these guys will straight up say that they don't NEED any help. They have all the help they need, right there on the pedophile "support" websites, on which they share conversations, such as their ages of attraction, how to get laws changed to abolish the age of consent, how to avoid being caught by the police for trading CP, how to groom a child's parent to get near a child, how to groom a child, and it goes on and on. If they were doing that underground (and I'm sure they would be), less pedophiles would have access to that stuff, and, though I'm pessimistic about pedophiles in general, that might just push a lot of them to get some real help, from real professionals. Maybe then we could see the results of that kind of thing happening. Right now, most of them just go online and get just what they want: justification for their actions.
/off soap box now hehe