----"You act as if there isn't 100's of people smarter on you working on this every day. Don't make that mistake. I have seen virus traced to a single group with some pretty inventive ways. Plus, people talk more then you would think."
This may be the case with many normal attacks, but once you start considering the sophistication of state sponsored attacks [which TFA is referring to], it becomes quite difficult to track down the true source. Most times this generally relies on the attacker making a mistake somewhere.
----"A lot of these attacks are very specific to targets."
This is also true "for now". Not all actors on the world stage have the same level of concern for collateral damage. There are currently no set rules regarding targeting; just a "gentleman's agreement" amongst countries that do not even admit to actively participating in cyber warfare in the first place.