Zero C's, one B-, 3.4 overall, interviewed at every top 10 I applied to. Grades are meaningless without context. What we want to know is, can you survive medical school academically. Yes, we want to grab as many students that have the potential to be great doctors in the future, but if you can't survive the training, everything else is moot. There are plenty of doctors with C's, D's and even F's on their transcripts. None are incompatible with not surviving medical school or being a bad doctor.
The real question.... But, why take the risk on someone when we have so many 3.8+ zero Cs students to choose from? Answer: because they have something that makes them special that the legions of academic automatons don't have. You don't need to be a 3.9+, 40+ student to get through medical school. The bar is much, MUCH lower. But your past academic performance is the best indicator of your future academic abilities, so yes, it does matter.