But that simply culls out workers who are less likely to be placed or less marketable to client companies.
Recruiters receive so many resumes each day that they look for any way to lower the stack.
For the same reason, recruiters tend to specialize in various industries and occupations. We can't be all things to all people. For example, I placed a senior account executive with a small dot-com a year ago. This person was 29 years old, and had 10 years of work experience behind her. Plus, she had only two years of junior college and no degree.