I think that what Christopher means is that adding a licence makes the developer's wishes clear. When you put a permissible licence its obvious you don't care what people do with the code, but if there's no licence at all it *could* mean you don't care, or it *could* mean you do care but just forgot to say it. In the case with no licence, there will be people who would like to use the code however they want, but stop because they're not sure the developer would accept it. This is not a problem with anyone in this community, who knows the code is free to use for anyone. It is more for people who find the code without knowing anything about the developer.