Lots of re-orgs is also a pretty big indicator. A lot of VPs/directors need a reason to exist and they create that reason with reorganizations. This is basically the enterprise equivalent of pushing the food around the plate to make it seem eaten. With a re-org you can shed or minimize expensive to operate systems that don't generate a lot of clear value(i.e most tech-debt).
Out of curiosity, are you saying that most tech debt is systems that don't generate much value?
If you had asked me, I'd probably say that tech debt is mostly systems that do generate value but are built poorly or in a rushed manner. Deadlines creep up, devs crunch, they ship a "working" product but it has design flaws that manifest as technical debt.
But now that I think of it, I've definitely also experienced what you're mentioning (I think). I've worked on projects with questionable motives that ultimately end up cancelled or abandoned. The leftover code remains and continues to confuse newcomers.
Sometimes, there is also functionality grafted to the wrong place in the system, or on to the wrong system. This can happen for a lot of reasons: expediency ("we have to foo the bar, why don't you implement it there as the release window is just right for our purposes"), bad design, or changing requirements.
If it stays there for too long, it will complicate the design of the underlying system because it has to be kept alive for daily business to go on. Such features are sometimes hiding in plain sight, and are actually causing a lot of pain or cause long-term risks, but we are too shy or spread too thin to address the issue. And why should we? After all, it works at the moment.
For that I always remember the fable, where animals have bought all those expensive shiny musical instruments, but nobody knows how to play.
They are trying to emulate an orchestra, by rearranging the seats, in the hope that the right seating will make make them sound good. But the orchestra cannot play for the lack of individual skills and lack of the leadership.
I saw in enterprises, they are buying all possible software licenses, but nobody knows how to use them. So the management is constantly shuffling people and churning technologies, in the hope something sticks.