Complicate everyone else's life: Allow the origin to be set by the user, too.
On the other hand, you often want to stick things at, or relative to, the center of the screen. If you want an edge, it's random which one you'll want, and addressing them consistently makes sense (windowHeight/2, -windowHeight/2, etc.)
manim does the same thing. It's super-intuitive to work with relative to anything else. manim also has shorthand macros like LEFT (which is a vector of (-1,0)), RIGHT, etc. which actually make for very readable code.
It makes some things so much easier and clearer, especially drawing static symmetric designs, where you can just specify both positive and negative of the same values to get symmetric points.