I mean, that kind of makes sense, since those are likely just required humanities courses for the "more difficult" science majors. Assuming those students are used to working harder for their A's, they'd have a competitive advantage in the more lenient humanities grading.
I’d think exactly the contrary: science majors would approach a history of science course expecting a history of discoveries leading from the Days o’ Ignorance to the Present, the Frontier of Knowledge. Or at the very least they’ll expect the course to be an internal history: history as told by scientists, not historians. But any history of science class that’s history is likely to be looking at questions of interest to historians, which are squishy, interpretive and don’t automatically privilege the Present state of knowledge as inevitable because it’s correct and science finds correct answers.