It's debt in that we pay interest on it. Resources that could be spent on the here and now instead go to maintaining the idea that's not getting paid off.
But as jerf said, it doesn't have to be that way. It's just an idea file, not debt, unless you pay interest on it. If it saps your emotional, mental, or physical energy, then it's debt. And that may depend on your personality, not just on having "that kind of thing" laying around.
Oh, sure. I have a zillion ideas. Most, I ignore. Some, I pay interest. This article prompted me to finally stop paying interest on The Tragedy of Obi-Wan Kenobi - admitting I'll never get around to writing and producing it. It'd be lots of fun - a retelling of Star Wars as a revenge story, with Obi-Wan Kenobi as the ruthless villain (nothing actually changes except perspective), done as a comedy musical that also explores my personal history and the relationship of art, artist, and audience (with questions of ownership addressed).
Great idea. Not gonna do it. So I should stop doing any work on it.
