Its this one. And the reason is that if steam sells a game at $10 and humble sells you a steam key at $5, steam gets no profit and is 100% responsible for the bandwidth when you donlload it, for hosting the page, for the market, etc etc. Basically steam doesn’t want to assume all the work with none of the reward. Which I don’t really see an iissue with.
Exactly! Pirate Software talked about this a while back. Steam doesn’t want you cutting them out, and then them still being responsible for the bandwidth to download and host your game.