Telephone: I'm here! I'm here! Pay attention!
Me: $workplace, $myname here.
Technical Recruiter: Hi! I'm $name from Workbridge Associates, and I'm specializing in placing DevOps engineers in the Boston area. Let me tell you about a guy I have. He's at $company right now, and he writes Chef cookbooks for JBoss in their AWS environments. He's also got several other great qualifications. Are you hiring right now?
Me: Let me ask you one question: what's the difference between JBoss and AWS?
Technical Recruiter: [pause] Uh, I don't know.
Me: Then we're not hiring right now.
Very long pause. I hear chit-chat in the background.
Not Very Technical Recruiter: AWS is a web service... and... jayboss is a web framework.
Me: We're not hiring from you right now. Bye.
This is a true story, and it happened just a few minutes ago. Minor changes have been made to protect the clueless and innocent.
(To answer the title question: you expect a used car salesman to be able to drive a car. Technical recruiters don't even know what they're talking about.)