It's not just bad coders, management is also very responsible. If management doesn't make sure code is at least getting documented and shown to co workers, the

It's not just bad coders, management is also very responsible. If management doesn't make sure code is at least getting documented and shown to co workers, then a lot of bad code gets written only one person understands and can develop into the shape of his own fetish, and become a problem when he leaves. The second point is that I have seen very senior programmers, as in years, e.g. the guys with multiple decades of experience, that are quite used to dealing with this. When they take code over they can read through it, add the necessary comments, and document the structure, and convey it to others.