I don't think that's actually true. If you look at a lot of their past projects, the real clever monetization comes after release, and very often they release piles of cool content entirely for free when they could easily have charged for it. They also spend much longer in development than is strictly necessary, and that tends to not make sense if your goal is to earn money efficiently. As a company they clearly understand monetization, but I don't think it drives their development process.