I doubt Joel Spolsky was equating legacy code with technical debt in this quote. Not all technical debt is robust and well tested legacy code. Chromium for ins

I doubt Joel Spolsky was equating legacy code with technical debt in this quote. Not all technical debt is robust and well tested legacy code. Chromium for instance has code from the original KHTML written in the 90s, most of that remaining code is reasonable and makes sense today. If it didn't someone would have replaced it.