Instead of placing all the blame on Larian, did you read the part which said:
Top-tier developers and publishers usually have contractual obligations with their retail partners that oblige them to offer the game at the same price digitally and in retail. When they don’t have such contractual obligations, they are still encouraged to do so, or else their games might not get any exposure on the shelves in your favorite shops.
That should be no issue on D:OS since there was no need to have a retail partner which bound them to such nonesense rules. Also they have known about the GOG release when they selected the retail partner.
Quote from there 80$ Tier on the kickstarter page:
"Digital copies will have to be downloaded via your preferred digital retailer such as Steam or GOG.com."
At the time when the kickstarter was a success GOG's principles where that 1 price for all regions.
See this
http://www.youtube.com/watch?v=nRdfYwvGTos or this
http://www.youtube.com/watch?v=dvaNgCTncLk.So no i don't accept this as excuse.
(fixed typos)