It's seven o'clock at the oasis

Every Thursday at seven o'clock I'm on the internet trying to cheer myself up, probably by looking at Disney vacations. Every Thursday at eight o'clock I go through a soul wrenching debate as to whether I should watch:

• The Office

• Tim Gunn's Guide to Style

• L.A. Ink

• It's Always Sunny in Philadelphia.

L.A. Ink isn't my favorite show, but they don't re-air them very often. Everything else I can catch at another time, or online. My question is why do all of the shows vie for the same time slot? Surely most of them know that they can't compete with The Office. Why doesn't someone just say "Fine, I'll be on at seven & I'll own the time slot?"