I suspect that the attraction of the physical copy for many of the Kickstarter backers like myself is because we wanted a copy of the game that doesn't require an internet connection and one we know will always be there regardless of whether Steam or GOG is in business.
You do know you can download
once from gog and then never have to rely on that service ever again do you? I admit I personally prefer not needing a client process in the background or permanent internet connection when installing/playing a game, and that's exactly why I like gog. Additionaly, digital service means no data corruption. Ever. Unlike DVDs (which contain a LOT of error correction code and will eventually fail to work one day). Plus it's the easiest way to get updates.
It's also why we put it on GOG.
Glad to have it confirmed. But why has gog not announced a thing?
The short answer would be because Steam sells a lot more so they figured it's more popular so the CE is Steam. I do agree they need to make money and GOG is not popular enough because all the AAA games fear DRM-free like the plague but hopefully with GOG-Galaxy, GOG can start to really pick up pace and start overtaking Steam. That and Larian is a small team and it seems like supporting multiple digital retailers is a huge pain for them.
Long answer here:
https://www.kickstarter.com/project.../comments?cursor=6958986#comment-6958985Well said.