Earlier quoted context omitted.
That's not true. Even current Macs with IGPs can play nearly any game at low settings adequately.
I'm sure game developers are really looking to capture the "low setting adequacy" market.
The Witness has has a peak of less than 5,000 players at one time so far.
The top two games (and basically the only active "pro" games at the moment), which together have about one million players playing at any given time are both carefully tuned to run on toasters according to Valve's hardware survey.
I like Valve's current micro transaction model. You can buy cosmetic items, but that's it. I can't speak for DOTA2, but in CS:GO they don't impact the game negatively like they did with TF2. Trading from free drops also allows kids and poor people to participate in the economy, which allows them to make more money for Valve than begging mom to buy a $60 game would.