I personally have only scored straight-100%s in a single course (Python programming), and that was only because I was relatively an expert in the material before the course began.
Well, the only two people I personally know who would get all 100s are Peter Norvig and Sebastian Thrun, and I personally wouldn't mind hiring them!
Of course, in reality, Peter Norvig and Sebastian Thrun are working on projects that have long time horizons, e.g. self-driving cars and search. So perhaps you're still correct: The people you would hire to bang out code to meet a short deadline are probably different from the people you would want to work on your long-term technology bets.
In general, I disagree that knowing a topic incredibly well is necessarily overfitting. Deep knowledge can only aid new insights. You often hear about mathematicians and physicists who think by inhabiting their own mental world, composed of insights that they hold so deeply that they are _intuitive_.