bansama: The only real difference between that site and this one is that it has a larger number of members.
I think another factor is the catalog in question. The 13-year-old crowd who plays Halo regularly and scream to their mothers that they "want some f**king chocolate milk" without having the decency to mute their mics aren't interested in the classics, and the ones that are act in a much more dignified manner. The people who come here either grew up with these games when they were little or are interested in playing games like they used to be made, for an inexpensive price. To enjoy games such as these requires that you either be old enough to know what they are and have the desire to play them, or be mature enough to have an interest in playing older titles.
As time goes on and the catalog gets bigger, more and more games that were made in the 2000's will be put on the site, which will probably attract some people who have not entirely developed maturely. They may bring with them posts like that one guy who posted suggestive photos of girls he liked. If a moderation team is going to be formed, it should be made of dedicated users who know first hand what is well-intentioned and what isn't. Many of these users have displayed superb moderation skills, answering questions for new and experienced users, advising users when their conversation gets a little too rowdy, and so forth. If we ever get to the point where it is a necessary evil, these users would most likely be more than happy to take up the mantle and help safeguard and regulate the community they know and love.
For now, we are fine, so live it up, but don't get too obnoxious. Everyone (Well, almost everyone here) knows what is proper Internet etiquette and what isn't.