Exactly, every software solution creator has a choice: be like MongoDB - free, open source to gain traction and users, hoping to monetize this somehow or be like, say, Datomic - fully commercial, less popular, less users, but with viable business model from day 1.

Sometimes the "open" route works well for founders - see RedHat, but that's not easy. Prior to AWS there were also others who were trying to earn money on someone else free product. In the pre-cloud era those "unfair" competitors were easier to beat, AWS is indeed a game changer here.