Because they use questionable tactics. While you can't be seen to buy your competitors internal phone book from a disgruntled ex-employee and cold-call of thei

Because they use questionable tactics. While you can't be seen to buy your competitors internal phone book from a disgruntled ex-employee and cold-call of their developers, you can use a recruiter who does that and thus get the same benefit without the reputational and legal risk the first approach would involve.