They sometimes did. It just wasn't super-common because people expected the single digits to be populated by broadcast channels (in fact, they often moved UHF c

They sometimes did. It just wasn't super-common because people expected the single digits to be populated by broadcast channels (in fact, they often moved UHF channels to single digits so they'd all be in a continuous block). When I was little, the local cable company in Dallas used Channel 1 as a tutorial channel where they looped videos showing how to operate the cable box and its remote. They eventually killed that, though, and just left Channel 1 empty. In other localities, they have actual programming on Channel 1. For example, NYC had the news channel NY1 on Channel 1 until 2010.