The original article deals with the issue of contamination and references that even running your own email servers, around 50% of your mail will still go through google servers.
The people opting out here are the digital equivalent of those attempting self-sufficiency, growing all their own food and making all their own clothes. It's inconvenient, clunky, and you still need to buy stuff.
The issue here is that due to network effects, Google (+ FB, Ebay, Twitter, Amazon) provide more utility as the monopolies they have inevitably grown into. That means they are a form of vital infrastructure, not competing businesses in a diverse marketplace. (If we don't like the idea that they are 'too big to fail' and actually should be protected, a glimmer of an alternative is provided by China which seems to have stood up functional alternatives to these in a fairly short period, albeit mandated by regulation.)