"That said though, I wonder if there is a way a big corporation can avoid this path, they'll have to monetize somehow and once they're monetizing they'll have to do better and better every year of they will look like they are stagnant."
The way to avoid it is to align the incentives of customers and users, ideally making them one population.
Google faces the same issues that FaceBook does, but less so. With targeted advertisements, the user has at least indicated their intent to buy something: they want something, the advertiser wants the same thing, and both their incentives are at least partially aligned. The happiness breaks down when the incentives come out of alignment, eg. when advertisers advertise (and Google collects money for) things that people don't want to buy.
Apple has a more pure form of this. Its users pay for products - the user is the customer. And so Apple does everything they can to keep them happy. That's why Apple customers tend to be fanatically loyal: they want a good product, Apple derives all their revenue from giving them a good product, and so Apple has every incentive to keep giving them a good product.
Note that this doesn't preclude Apple from pissing off other groups. They're notoriously developer-hostile, for example, because Apple doesn't see third-party developers as being critical to its bottom line.
Follow the money if you want to see who a company is really working for.