We have to remember that those are real people and not just percentages of traffic that are affected when we make decisions like putting a captcha up against every visitor from certain countries. I like to think we were already doing that, but it is good to be reminded.
However, I am not quite sure I am getting what the author is suggesting when they say that sites should forgo a CDN. Maybe I am biased, but if you thought latency was bad when a datacenter near you went down for maintenance, try having to go all the way to the sites origin in New Jersey for every request. I am not aware of any way besides a CDN (or a CDN like setup) that would get you good performance for people in all countries.
So I get the frustration with the captchas, and I get the frustration with the lack of multiple datacenters near you, but I wonder if you will make things worse for yourself by advocating to not have a CDN.