The point is that at a certain point writing the code gets easier than writing a spec.

Lets say you outsource this site, and you send a spec to the developer the spec looks something like this: 1) These 27 actions should only be used by an administrator. 2) All users must register with a valid looking email and choose a username.

Every one of those would still take one line, wouldn't it be simpler to just code the damn thing yourself???