Ward Cunningham's original idea of tech debt (see [1], a beauty of concision at just 300 words) is that iterative development distorts your code because you start writing code before you know the requirements, but even so, it's better than waterfall. "The traditional waterfall development cycle has endeavored to avoid programming catastrophy by working out a program in detail before programming begins. We ... [instead use] the alternative, incremental growth ..."

Today, the term "tech debt" includes sloppy code, shortcuts, novice code -- really any kind of bad code. The original conception of tech debt is more limited and tied to waterfall vs iterative process choices. [2]

[1] Ward Cunningham, The WyCash Portfolio Management System, OOPSLA 1992. https://c2.com/doc/oopsla92.html

[2] George Fairbanks, Ur-Technical Debt, IEEE Software 2020. https://ieeexplore.ieee.org/document/9121630