Further to Oratie's comment, the reason is secrecy or IP protection, in a way. The very reason ASCII .lib file is converted to binary .db is to protect the numbers (which to a trained eye can reveal a lot on the process, etc). It is not normally acceptable to reverse this. Only RnD teams of tools supporting .db directly "may" get this data for debugging purposes..
Having said that, many tools do provide access to relevant attributes and lot can be learnt about what is in there that are needed for usage. I am not aware of whole scale conversion, but if you are looking for anything specific for a custom script , it might be be possible.