lolplatypus: It's one thing to have that situation, because I settled on an unsupported distro. That's fine.
To be frank I don't think that's fine at all.. it's something I put up with somewhat begrudgingly (less so back when Judas & vangog were the unofficial but super helpful channel for support that didn't shoot you down for having the wrong distro) because there's not much choice. Things could be much better. But I understand your point.
Having being on your own if stuff breaks be the default user experience, on the other hand, would be unfortunate. It wouldn't change much for me, either, but I'd be reluctant to call that "support".
Sure. Sure, it would suck for anyone who's invested in Ubuntu / derivatives and wants to keep using them.
Then again I could sort of see myself in GOG's shoes (or really anyone's who's got limited resources to support proprietary software developed by third parties) and I probably wouldn't hesitate too much to switch over to something else if the currently supported distro decided to pull the rug from underneath. Same thing I do as a software developer, sometimes I just have to tell that I'm not going to fight uphill to support some system that does not want to be used for the given purpose.
Still, the optimist in me thinks that they *could* do something reasonable and give up this blessed distro nonsense. I've never asked my clients about their distro or system specs (well, I happen to know what distro they use but that's not the point), if they report an issue then I try to reproduce it and fix it. If I can't, then I tell them I can't, and that I might need more info.
EDIT: Also, it's not like GOG's just doing what everyone else is doing. Some game developers might have their "blessed distros" but many of them don't give a shit, you use what you like and they still support you if they can. Mozilla doesn't give a shit, they still support you... as do countless other companies. I think GOG is the outlier here when they decided that you must have a particular brand stamped on your Tux if you want support.