That is a misreading of his post. What he says in there is that users from GAAS / F2P games buy much less games than the average (if at all), so basing your full audience on them is not the best thing.
Basically the audience for those games and the audience that buys artsy Indies is quite separated.
Which is why I find the claims that EGS will help developers to be inaccurate. There are different types of developers that need different things. AAA devs don't have a hard time getting their game in front of eyes so the store cut and moneyhat is good for them. Mid tier studios or large inndies might appreciate the money hat but they also need exposure and a large consumer base to grow their brand. Smaller Indies need exposure first, and they'd be gated off by the duration of EGS. Making a blanket statement about being good for developers is just misleading.