I totally agree with this and this is actually something that my Engineer Brain and Product Brain are constantly in conflict about. I ran gitignore.io for 6 years and it was not "hard" to run. It was two commands on a web server. The problem was when I was on vacation or at work and AWS/Heroku crashed and I got flooded with GitHub issues/Tweets telling me the service as down[1][2]. All of a sudden, I have to go take a look.
Martin Fowler said something in a talk a few years ago[3] and I think it speaks to this exact mindset. This post is lacking any economic reasons for people to run their own mail server — tell me why me running my own mail server saves me time and/or money.
As another tangent, I'm actually looking at running my own mail server. For me, it's privacy which coincidentally is not even mentioned once in the article.
[1] - https://github.com/toptal/gitignore.io/issues/369