It's probably a good idea for all IT people to have a working knowledge of how to debug DNS issues.

DNS has historically been a vector for significant security holes and it's likely that this will continue to be true for the indefinite future. These holes also lead to other vectors in nearly every other protocol like SMTP. Even the CA system used for HTTPS is highly dependent on a basically insecure protocol. (Would you notice if your bank bought a DV certificate instead of OV? likely not)

So, perhaps it's not such a bad thing that it seems hard to learn to those who don't have enough interest, since even now we see people building DNS things without taking the time to really understand the history of things like port randomization, cache poisoning, AXFR, etc.