They're making a joke about the misspelling of Matt Damon. "Daemon" is a computing term [0] and /sbin/ is a folder that you might want to put a Matt Daemon in. (Also, daemons are often named with a "d" at the end, like "etcd" or "mattd".)
If this were Reddit we could keep this going until we had a meme about Matt Damon running in the background of movies, and a whole corpus of images where he's been photoshopped to be doing just that.
Now I'm kind of regretting this conversation isn't on Reddit.
Yeah, but I'm not one to force conversations. Maybe I can gently steer it the next time a Matt Damon relevant post comes up in gifs, assuming I get there before it's swamped in comments.
In the meantime, I guess I could make some gifs. Because that's a much better use of my time than research, learning, or taxes...
On one end of the spectrum, you have people who doubt that we landed a man on the Moon. On the other end, you have people who think we had a man grow potatoes on Mars.