Nice analysis, but I think you missed the most important difference between real debt and technical debt: with real debt you owe someone else; with technical debt you owe yourself.
Not to yourself; you often inherit the debt from previous developers (who may have left).
The project accrues technical debt.
And it owes it to the users.
Because, ultimately, that's who all these FTE hours (the currency borrowed!) are going to.
By taking a shortcut now, you make an implicit promise to the user to rewrite things later (on behalf of the project).
It's the user that suffers if the debt is not repaid (by experiencing bugs, missing features, slow releases, paying for higher headcount to fix bugs, etc).
Shortcuts don't become debt unless the user is affected. If it's stupid and it works, it's not stupid.
And it is the user that will dump your project if that debt is never repaid.
I had an aha moment a few years ago when I realized that technical debt is not taken out by the development team; the development team are the ones making the loan. The debtor is the product/sales team, who got their feature early but now have to pay a little more (in delay or lack of functionality) for every other feature.
Ideally, a dev team delivers feature value at a particular sustainable rate. Think of that as your product team’s ‘income’. Now, if the product team needs a feature early, they can have it if they take out a loan - they can have the feature built without sustainable integration into the codebase - but it will reduce their effective income because future feature delivery will be slowed by the friction of the incurred debt - the interest payments.
Don’t let the product owners make you feel like you have to deal with the burden of debt they took out! They owe you the time to clean up the mess they demanded to get their features faster.
