It depends on what the recruiter's goals are. If you're trying to build a brand and establish longterm relationships with people, then, yes, spamming the world

It depends on what the recruiter's goals are. If you're trying to build a brand and establish longterm relationships with people, then, yes, spamming the world is not in your interest. If you're working for an agency, have a quota, and are doing your best to stay above board and not get fired, then spamming the world is in your interest. The design makes it easy to contact multiple people at once with seemingly personalized messages. In particular, I can specify the type of greeting and a template, and LinkedIn will fill in the person's name etc.