Adding TODOs to your code is a double-edged sword. While they provide valuable informarmation, they're often simply left to live in the code as a parasite. The idea of TODOs and FIXMEs is to provide some context to other developers and to yourself about a missing or not working code block, which will be eventually refactored and fixed. It all seems fine if only the developers are responsible enough and have the time to made the changes.
In a perfect world, a TODO should and would be handled in a matter of days, maximum. But that's not the case. Developers are preoccupied with their own tasks and own problems. To be able to do the problem with satisfying quality, one developer is tasked with, he should concentrate on one task only. We all know that multitasking is conterproductive, and TODOs are a catalyst for multitasking and context switching.
While TODOs can be seen as a non productive practice, they can have positive influence on developers if taken with proper responsibility. We all were in a situation, where presured by time and deadlines, we decide to finish the task using the fast and non-optimal solution, in exchange of introducing technical dept. Technical dept is a necessary evil, an assessed risk, which we dedicate time to remove periodically in the future. How can you track your technical dept? With TODOs and FIXMEs.
There are tons of tools to track TODOs in the code. Almost every IDE has an integrated TODO tracking. Webstorm, for example, will even warn you before commit, that the code has an unresolved TODO or FIXME comment.
I have to confess - I stopped using TODOs. I prefer to compensate on time and deadlines in favor of complete and production ready code. I tried to find a balance between them, but it didn't work (for me). So, choosing between shipping incomplete code just in time or taking a day more to refactor and finish the task, I would choose the second in 99% of the time.
That doesn't mean everyone should stop doing it. It may work for you, but remember - dedicate part of your time to handle them and make it a habbit.