While I have seen such a distinction (see my sibling comment), I think it has peaked, and is on the decline. Furthermore, it has more often been outspoken members of one group excluding the other rather than systems researchers or theoreticians not calling themselves "computer scientists."

I have not seen this distinction in academic computer science.

Computer Science often has a different curriculum depending on whether the CS program at the university grew out of its Math or Engineering department. I think this helps explain some of the wide variations in what is considered a "CS" degree.

We may be talking past each other - I am not talking about curriculum's, but the terms that those who do computer science research use to describe themselves. eximius made a claim I have seen no support for. All systems researchers that I know, including myself, consider ourselves computer scientists.