I also find that a debugger encourages a technique of just tracing through the code until "a-hah, that's where fooBing get reset to dingy. I should add a clause

I also find that a debugger encourages a technique of just tracing through the code until "a-hah, that's where fooBing get reset to dingy. I should add a clause to reset it to dingy only if barBong is set." Someone actually skilled in their craft would say: "a-hah, that's where fooBing get reset to dingy. now I understand what's happening, let's understand why". Remember, this is kernel code we're talking about here. In user-space, I rarely need to use a debugger because nearly all issues are caught during initial development by unit and regression testing. However, there are still times where something goes terribly wrong -- sometimes in vendor code (or in the case of the kernel, hardware) -- and I wouldn't give up my debugger for the world.