Earlier quoted context omitted.
I am hesitant to write this, because in general I agree, but let's say a product manager stops a feature short of completed in some sense, even though there are some aspects which would make the feature more robust, secure or optimized, the code gets released and one would need a tombstone as a visible nuisance and indicator for these aspects, wouldn't it? I mean the best place to communicate important ideas and warn…
If you've let a PM stop a feature short of something you as a dev think is rather important, you've already failed to some extent as a professional. There are ways out of such a mess, but it's better to avoid it to begin with, and if it really couldn't be helped, to have a paper trail if not only for yourself then for the benefit of others. Coming to the project as a new hire, I'd find a "TODO[3 years ago]: maybe add…
The thing is, you might also be not reading that piece of code for the sake of performance optimization. In this case such TODO is a testimony of premature optimization being evil: like, the code has obviously been fine for at least three years without any smartypants optimization that the developer at that time envisioned to become necessary.
Though yeah, it could have equally been just a 3-year-old ticket in the issue tracker. However, you won't learn about it when casually exploring the code.