cmdr_flashheart: No, GOG didn't invent, nor introduce, regional pricing into the world.
As to the success of the game, the vocal minority always makes something seem like a bigger problem that it is, so who knows.
It is fair to criticize GOG for accepting to sell a game with regional pricing, specially with a $=€ policy. They can of course not be blamed for the developer to choose that pricing model, but they can be blamed buying into it.
As for the success, of course nobody really knows. However, I feel that people who would buy this are 1) fans of the old games, which happen to be the vocal minority for the most part, and 2) people who want their strategy fix with fancy graphics
now, and typically this second type don't give a shit about DRM and will buy on their usual/cheapest store.
I bought Omerta on relase (or preorder maybe? can't remember) to support the coming of new releases to GOG. When I did, I didn't do it with this kind of release in mind, but then again that's just me.