There is absolutely no difference between the GOG and Steam versions of this game (at the time of their release), the game was released on GOG first by Night Dive in-fact, and then later on Steam, yet for some reason they got the new SVM version of the game, and we still don't. This isn't just any publisher either, it's Night Dive who was responsible for bringing System Shock 2 here and Wizardry 8 here and to Steam. If their blowing off GOG and snubbing it's customers then it's an issue.
If people want patches instantly, they probably will need to buy the games either directly from the publisher, or directly from the distribution platform that the particular publisher uses as their #1 distribution mechanism because the platform that gives them the most sales is probably going to end up getting their developers service/support first and foremost before other distribution platforms if custom work has to be done for every different distribution of their software.
That's a self-fulfilling prophecy, really. Just admitting that GOG will always be slower providing patches and if you don't like it go somewhere else? That's likely exactly what most people WILL do, or rather have done, you know rather than wait 3 weeks for one patch like I Have No Mouth, they'll go to Steam and never buy here again.
And no I don't support Steam-style auto-patching, but if GOG really wants to get into new games, they'll need to understand that most new games get patched ~constantly~, and people who buy and play them are not going to wait around for weeks for one patch to be applied, they'll ditch this site and go back to Steam for the same games, just saying. I'm not saying you need instantaneous patching, but you need to be punctual.
And yes, maybe it does mean GOG should look into recalibrating their relationship and contracts with devs regarding patches, instead of just a "whenever we get round to it", you know like a clause which states that if you wanna sell a game on GOG, you need to provide patches and not a week after every other distributor on the net.
EDIT: And I'm only saying it because I like GOG and want it to do well.