LonePaladin:
The problem really is that the definition of "gaming" covers three disparate fields: tabletop RPGs, console video games, and gambling. The last version is probably what most schools and employers seek to block, but this ends up including the other two simply because they use the same term.
Having worked on that end of the line (IT) it really is a matter of "Anything that could reduce work productivity".
So, someone spending time at work playing roleplaying games? Yeah, it's gonna get shut down. Even gaming news sites and gaming message boards which are just about talking about video or roleplaying games (like ENWorld, SJGames, RPGNet, etc) are gonna be on the "No go" list.
See... when you sign in that makes a cookie. Those are looked at by IT. And it's their job to add all those sites to the 'no go' list. Some banware can even detect when a cookie is being made from a No Go site and then shut that site out, even if you're using a VPN.