No, the Cyber War threat has not been highly overrated, and in fact may be underrated. Today's society has become very dependent of various electronic devices as well as the Internet. Many people would not know what to do if the Internet became unreliable. If banking or the power grid became compromised by a criminal chaos could ensue.
The Cyber War threat has not been highly overrated. We can see how this is true just by assessing how many times each of our own computers has been infected with a virus. They are always from outside sources. It does not take much to understand that there are people who want to destroy the computer resources of major corporations and national security.
The majority of finance is conducted through the Internet now from stock markets to banking, there is a massive risk of Cyber Terrorism to be able to destroy a Nation's entire economy, I think that Cyber Threats will only increase as our technology continues to improve and it is going to be a big issue in the upcoming decade.
No, people that think it is overrated are very wrong. The "silkroad" AKA the black market that was just shut-down not too long ago was one of many things that have been sparked online. Cyber war is hard to manage, but is necessary evil. The Bitcoin, and other currencies that support crime shouldn't under estimated.