I could be wrong but given how fast things change in this business, this seems to test very micro level skills not the learning and adaptability skills.
What if a guy could, given the business or technical issue the code solves, write something faster than he could fix others code?
May be the job is about heads down coding so this bug fix test is appropriate..
How is debugging a "micro level skill"? Jumping into an unknown project/system/whatever is something you will likely have to do at some point. (Sometimes it might be code you wrote yourself years ago, but revisiting without any context makes it feel unknown.)
Is this hypothetical guy always writing 100% correct code?
What if a guy could, given the business or technical issue the code solves, write something faster than he could fix others code?
May be the job is about heads down coding so this bug fix test is appropriate..