This! Also my guess would be Kernighan or Pike aren't (weren't?) deployed into some random codebase every now and then, while most grugs are. When you build something from scratch then you can get by without debuggers, sure, but foreign codebase, a stupid grug like I can do much better with tools.
Most of us aren't Brian Kernighan or Rob Pike.
I am very happy for people who are, but I am firmly at a grug level.