Personally I _love_ debuggers when coming to new codebases. I view code in the process of execution as the natural state of a codebase. Instead of hoping around through source code by hand, why not step into functions, continue execution, and let the program flow do it for you? Most code only has small parts that are important and with debuggers I can usually find those parts right away.
I don't blame Torvalds for not wanting to use a debugger. He doesn't like them and doesn't want to support them. That's his choice. But I find it odd to just categorically dismiss them.