That's it in a nutshell. When GOG launched, it was officially Good Old Games, and sold only old games. No new games, no indies. Just classics from (predominantly) the 1990s. That attracted an audience of people who played those games in the 90s, which meant that the average age on the GOG forums was a lot higher than on any other gaming forum. The higher average age meant that the forum was generally a lot more civilized and that people in the community generally expected "proper behavior" from one another.

As GOG grew and expanded into indies and newer games, they naturally attracted a wider audience, but by then the existing core community had grown very solid, so most newcomers sort of slipped into the same mentality, sometimes after a period of acclimatization. The forum has always policed itself, more or less, so when people come from the "outside" and break the community's unwritten code of conduct, the community makes them aware of this.

In a nutshell, this means that even though the average age of the community is probably closer to other gaming forums now, the way the community was shaped from the beginning has ensured that people still conduct themselves here with more maturity and less aggression than in most other places.

I agree, most of steam boards are just useless and/or filled with random nonsense and rage, but there is a non-negligible part of insightful people who helps fix problems for those in need.
The codex is mostly an horrible world of hurt, last time I lurked there it was really a disturbing experience (some kind of nonsensical bigotry seemed to drive the conversations there).

Always in the gentlemanliest way

Originally GOG only sold Good Old Games, and the thing about old games was they generally had certain characteristics that distinguish them from many of the new games. First, they were harder, limited lives, no autosave, monsters were tougher, things of that nature. In many cases you had to really think, and use every resource available to you to overcome obstacles. Second, you had to be patient both in play and in installation/loading. Not everything happened boom, boom, boom. A lot of old rpgs and adventures also required diligence, many didn't have an automap, or a quest journal, or hints on where to go next. There were no flashing arrows saying speak to this one character. This was also before the internet in many cases (or at least before an easy way of searching the net), so there were no walkthroughs, no websites that laid out exactly what to do next, no instant solutions. Instead it required thinking, problem solving, aggressive player effort. The other part of being patient was the fact that game installation could take a very, very long time. And patching wasn't always possible for any bugs encountered. Third, many also required significant reading. Many of these games were before voice acting was possible/feasible, so instead they relied on text to tell the story. You also had games like the DnD games that offered the players an abundance of choice that over 40+ hours (or 80+ hours even) ended up being a lot of text and that's not even counting the manuals. Tutorials were often nonexistent, sparse, or spottier than hell, instead there were manuals. 100+ page manuals. Sometimes more than one for a single game.

So when GOG came about and only sold Good Old Games, you had this draw, this crowd that they specifically catered to. The only people who visited the forums were those who were inclined to purchase old games. They were players who had no problem reading, thinking, solving problems, being diligent, being patient. They were players who remembered paying 60+ dollars for a game and playing it and replaying it for hundreds of hours, placing value on a game and investing large amounts of time and effort as opposed to picking up 10 games for a dollar and never even playing them. They were avid fans who were ecstatic to find like-minded people, who were happy not to be looked down on for not just enjoying the latest new, new, new game (make it shinier, make it louder, make the grass more realistic, make the voice actors famous people, let's have this whole section animated, spend the budget on anything except content). These were customers who had a more mature mindset.

The thing about forums is they develop their own culture. They are societies in microcosm. People act the way they see others acting. People naturally tend to be social animals and want to fit in. So here was this forum of maturely minded people, and new folk tended to go with the flow. Chatspeak was frowned upon and mocked. Intelligent discussion was encouraged. Kindness was respected and not seen as a weakness. Gifting developed as a natural response to wanting to share nostalgia, particularly for those who remembered being the only ones they even knew who played a certain game. People who were more inclined to trolling either gave up and left for greener pastures, or gradually shifted into actual community members. By the time new games were introduced and Good Old Games became GOG, the community already was a community and not inclined to change.

Or at least, that's my two cents. :P

Edit: Annnnnd ninja'd by Wishbone because it takes me too long to solidify my thoughts. Curse you Wishbone and your concise explanations!

We have Judas watching over us:)

He watches our backs .... waiting the good opportunity to push us with the thread in the ravine !
That sums it up :-)

It would be interesting if someone wrote a paper on this, maybe they would uncover reasons we don't expect at or perhaps that those that we do expect (like higher average age) didn't have any affect at all, it only was perceived that way.

This seems to largely be a +30 crowd and even the members who are younger adapt to the more mellow environment.

I suspect that the bulk of GOG's user demographic is between 30 and 40 years old, unshaved and wears glasses.

For the record, I'm 38, shaved, but I do have hair down to my ass, and I don't wear glasses but I have had cataracts twice so maybe I should. :D

Don't shave for 2-3 days and you'll fit in perfectly with the rest of us.

If I don't shave I'll be a dead ringer for Jesus.

Could be worse. If I don't shave, people ask me "do you work for the Taliban?". (this has happened quite a few times, mostly it's meant as a joke. I don't want them to ask me that at the airport though so whenever I fly anywhere, I shave my face baby smooth to avoid being targeted for "sand people random search")

You get mistaken for this? :P

You mean this?