I had this when I applied as a grad. I wasn’t clear what they were looking for so I asked if they were looking for algorithms and language agnostic programming ability, or whether they were looking for Java and Java standard library knowledge. They wanted the latter, just Java. I didn’t continue my application.
If I got that response I'd tell the recruiter that "I'm not an RCG programmer, I'm a systems engineer, and that stuff has no relation to the actual work I do." Than I'd ask them not to call me again.