I agree that proper logging can replace the need for a debugger in many instances, but so can proper testing, talented devs, unlimited time, unlimited budget, etc.
Under ideal circumstances (i.e. not real world), no one would ever need to fire up a debugger, but (most of us) don't work in those conditions.
Can you create world-class software using only print statements to debug? Sure. Is that an efficient use of your time? Probably not.
The bottom line is debuggers are just another tool in the development aresenal, and dismissing them merely because you can accomplish the same task in another way is asinine.