As a purely amateur C# developer, code that I write rarely gets to hurt people. (Well, open source projects aside.) As such, it’s fun to stretch the language a bit, find its limits… and then try to sneak past them. One of my first reactions to a new language feature is “How can I use that for a completely different purpose to the intended one?” The results are rarely pretty, but they’re lots of fun.
The chances of any of the code you see in this session being even remotely useful to a conscientious developer are very slim. You may well learn some interesting things about the C# language, but that’s a different matter. To put it another way: if you’re trying to persuade your boss that it’s important to send you for educational reasons, you probably don’t want to show him this abstract.