I think what is so wonderful about databases and data as a profession is that we oftentimes are the JOIN (if you will) between the high-level software (applications, code, etc.) and the low-level hardware (storage, etc.). Knowing nothing about either is just a time-bomb waiting to happen.

I find it interesting that you explicitly stated networking as something we should know relatively well. I definitely tend to agree with that. Do you feel that structured network learning (i.e. CCNA) is a benefit to a database administrator?