Information about algorithms is generally kept secret to prevent people from gaming the system. (there are some unwritten heuristics that I wish were written though, such as the inherent penalty for self-posts)
Can you elaborate on the self-posts bit?
I found this discussion about the self-post penalty from 2010:
As minimaxir said the algos are kept someone secret. The higher level concepts are shared in a manner to prevent people from exploiting and taking advantage of them (and I agree that they should be kept that way).