Yeah I thought you already sorta knew all this stuff, Jim... I don't work in games but I am a student of the broader IT systems industry, and they TEACH this stuff as part of the business curriculum. Appeal to large audiences, appeal to demographics with money, growth is everything and if you're not growing you're losing. Whole assignments based around trying to sell unpopular monitoring and other features as important services. In information systems in general, there have been quite a few situations where I've been asked with new and creative ways to collect data from people. Social media is not viewed as a tool, but as the most direct way to collect information to tune business and marketing strategies.
The reason why those three are the models for success is not because they are good games, but because they've done everything "right" when it comes to marketing, growth, and siphoning as much money out as possible.
To be fair, my school does teach a variety of approaches, and niche audiences are taught to be just as potentially profitable, but you're also basically taught "look at the rest of the industry and do what works."