I can't think of any code rot either. As long as it is built against the standard it tends to just work.
I also find the idea of using no libraries a big thing in more advanced users of CL. The more advanced of a user the more it makes sense that you can just implement it yourself (with only the functionality required) and know it works without having to leverage a library. Then again, the idea of CL is that things that tend to be bigger/harder to solve problems in other languages can be done simpler in CL because you can break the problem up different and have an easier to understand or implement solution.
I also find the idea of using no libraries a big thing in more advanced users of CL. The more advanced of a user the more it makes sense that you can just implement it yourself (with only the functionality required) and know it works without having to leverage a library. Then again, the idea of CL is that things that tend to be bigger/harder to solve problems in other languages can be done simpler in CL because you can break the problem up different and have an easier to understand or implement solution.