In a recent e-mail chat with GOG.com, GamingOnLinux.com asked them about supporting Linux games on their digital distribution platform. There response was that it would not happen in the foreseeable future due to their current business model and all the distros.
The response they received from Trevor Logino, the head of PR and Marketing at GOG stated;
Unfortunately not much has changed in our stance towards supporting Linux in the last few months and there is one main reason for that. Since our birth over 5 years ago we have always provided full customer support for all games we have released. That is not going to change. For every game we release we provide a money-back guarantee: if we can't get the game working on the customer's computer with the help of our support team, we return the money. The architecture of Linux with many common distros, each of them updating fairly often, makes it incredibly challenging for any digital distribution company to be able to properly test the game in question, and then provide support for the release--all of which our users are accustomed to.
Sure, we could probably release a client and sell the games and let Linux users worry about the rest. We don't consider it, however, a viable option for the business model we have followed so far. Apparently our model has its drawbacks, as we cannot make everyone happy, but, as of now, we don't plan on introducing Linux support in the foreseeable future.
While Linux does have a quite a few distros, they could opt to only support one or two, similar to Steam, but obviously feel that the expenditure of resources is not in their best interest at the time.