TLDR: Meaningless topic on old video
Day9 said GUI stood for General User Interface. This could be a genral error, but most believe the meaning stands for Graphical User Interface. Most professionals in any techinal field are using Graphical User Interfaces and not General (as in made for the general non-techical population((mostly not professional)) interface). From a tools programmer and IT professional this does hit my alley. BTW really just a worthless kneejerk reaction. Lets see what the masses have to say!
Please comment or flame, I don't really care