Interactive debuggers and printf() are both completely valid and have separate use-cases with some overlap. If you're trying to use, or trying to get people to use, exclusively one, you've got some things to think about.
I almost exclusively debug via printf / logging, and I am so stupendously ignorant that I have even written and published a multi-platform interactive debugger, to go with the compiler I also wrote (one of several, but this one was the most successful). Make of that what you will, I suppose.
