Implicit or explicit, you need a hypothesis to be able to start probing. Many issues can surely be found with an oscilloscope. Many others can't and an oscilloscope does not help in any way. It's experience that tells you which symptom indicates which class of issues this could be, so you use the right tool for debugging.
That's not to say that at some point you don't need to get your hands dirty. But it's equally important to balance that with thinking and theory building. It's whoever gets that balance right who will be most effective at debugging, not the one with the dirtiest hands.
That's not to say that at some point you don't need to get your hands dirty. But it's equally important to balance that with thinking and theory building. It's whoever gets that balance right who will be most effective at debugging, not the one with the dirtiest hands.