The name is tongue in cheek. It's taken from a NEJM editorial that attempted to negatively characterize people who just analyze data without doing the grunt work of collecting it as "research parasites".
(Obviously the editorial is gesturing at a real problem: that by unbundling data collection and analysis and, as is unfortunately typical, only giving credit to the result of analysis, there could be a dearth of data collection from lack of incentive. But characterizing pure analysis negatively is obviously the wrong response.)