It's funny to me as well. Being initially inspired by Yelp's dockersh I wrote a functional MVP of the same concept around 2 years ago. It used a custom Go sshd-proxy to spawn kata-container backed pods in kubernetes. I used it personally for a very brief period of time, and found it useful as a small timesaver for testing things. I wasn't comfortable with monetizing it though. After seeing a few of these pop up, I realize maybe I missed my chance to be early.

As far as self-hosting goes, it looks like there are some FOSS projects now, eg https://containerssh.io/