Why no half court line?

[Nevadaref]

If you look very closely, you will likely see that those courts have what is called a shadow line. It is tough to see on TV but the outside edges of the division line do extend through the logo.
Some preseason tournaments and holiday classics do have big sponsor logos that obscure the division line though, so you may be correct afterall.

The official has to make a judgment call is the answer to your question.