If the recruiter is given specific hiring criteria that are hard but not impossible to satisfy, I could imagine looking for people who fit those requirements an

If the recruiter is given specific hiring criteria that are hard but not impossible to satisfy, I could imagine looking for people who fit those requirements and persuading them to sign up would be a satisfying job of search, selection and salesmanship. But that's not what these Google recruiters are doing. They are trying to find any vaguely qualified people they can who are willing to dive head-first into the meat-grinder that is the Google interview process. And their job is mostly futile because that process will ultimately reject 90-95% of the candidates.