My point, though, is about confirmation bias. Most people don’t know a lot of people who turn on plaintext email as a point of habit.
It might seem like I’m criticizing the guy, but the thing is, there is a very real problem where people are looking at this from their own tech-forward perspective when this is a topic that affects many more people.
Average people tend to use what they have, I have zero "average" friend trying to get more supported features than there currently are.
And, by the way, most of my friends do not use html/CSS directly, or even indirectly use it besides some bold, coloring or the random photo attachment. Zero of them know caniemail.com, and, if they understood the point of it, zero of them would want or need it.
Average people seeing html in their mail doesn't mean they have an opinion on it, or would want more of it if they were told honestly what it does and who abuses it.
For another interesting datapoint: Of the plaintext-only and plaintext-strongly-preferred people I know, somehow almost all of them are German. I wouldn't call them "tech-forward" either, as many of them are specialists in other fields.
...and before the inevitable questioning I'm going to receive: no, I'm not German, and I know more people who aren't, with similar plaintext preferences.
It might seem like I’m criticizing the guy, but the thing is, there is a very real problem where people are looking at this from their own tech-forward perspective when this is a topic that affects many more people.