That's not really a license and more of a tl;dr. There's a lot of value in picking an existing license to ensure people know what's up, and also that it can hold up legally if you need it to.

EDIT: To clarify, yes, I know that putting it there makes it "their license", and if I were to use code from their site I would adhere to it. My concern is that, because it's not actively shown when viewing the code itself, and because it's a roll_your_own license, it impacts how comfortable I'd feel taking the code and using it as part of other projects.