In teaching our students who are in game development majors, I try to get them to think about game design broadly. Not just in terms of crunchy systems or neat hooks (which are important, of course) but also in how the overall context of the game as a product as well as a creative object might shape what they do. Monetization strategies have to be considered from the very beginning of the design process I think. You can definitely build games that are both player-friendly and highly monetizable (and one hopes profitable without being exploitive), but it takes intentionality and a keen understanding of how game mechanics and structure interacts with the stuff you are selling.