The OP is about someone still in college. I don’t look at the GPA of experienced people. But when you get a bunch of resumes from people with no experience and who are studying similar classes, the GPA can help the resume stand out. GA Tech sends me a book of resumes about an inch thick. Given that I do believe in a correlation between GPA and subsequent performance in the job I’m recruiting for, requiring a good GPA is a fast way to whittle that inch down to a few resumes to pursue.
With respect to the OP, it is clear that some prospective employers don’t care about GPA (or profess not to - I’d like to see how many 1.0 GPAs they would interview). And some do. So the answer is that if you want to maximize your opportunity, you should maintain your GPA. If you don’t maintain your GPA, there will still be some opportunity.
This is not always universal. My GPA was considered irrelevant for the research positions I was hired at. At the interviews, I was not asked to explain away my lousy grades. Instead, they threw hypothetical experiemental design questions at me.
I’m not an employer (but I could be one day!), but if two resumes in my hands had those numbers, I’d hire the 4.0 in history. My reason: regardless of the perceived relative easiness of his major compared to the physics guy’s, he still did enough quality work to earn a 4.0. Take away the majors, and you have a 4.0 student and a 3.0 student. Which would you rather hire?
I would not cut someone slack because their major was “harder”. I’d care more about the effort he put into his work than the toughness of the work (which, again, may just be a misconception). In the end, I’m going to care more about the GPA, as it’s a better predictor of the applicant’s potential than his major.