as was said, the harder classes may be more helpful in understanding your coursework later on, but also, the adcoms don't know that those other classes are easy and who are they to say that that isn't an actual interest of yours. i took several easy upper divisions (ecology, evolution, some sort of environmental class), and i still got in. it didn't hold me back in classes in med school either. while some of us may consider choir or piano "easy" courses, music majors still get into med school. what i mean by that is not everyone has the same interests in classes throughout undergrad, and taking 'different' courses than most pre-meds won't hurt you
med schools have their requirements. as long as you reach those, i don't think the majority of school scrutinize over every other class you've taken. yes, an interviewer may ask you about why you took it, but you come up with an answer and something good that came out of it