I was taught to use a debugger in college. Not much, late (it should be almost the second thing to teach), but they taught me.
Anyway, it's important to teach to DEBUG, not only to "use a debugger". There are situations where you can't debug with gdb (e.g. try to debug a program running 10 concurrent threads) and you need a different approach, like the old-fashioned printf.
I can certainly agree with you that usually one learn and make use of debug techniques much later that the first time you could use them.
