The point of the article was not the hostile AP, but to simulate a pervasive threat:
we would create a pint-sized version of the Internet
surveillance infrastructure used by the National
Security Agency... Porcello would become our one-man
equivalent of the NSA’s Special Source Operations
departmentThe broad surveillance of any practical intelligence apparatus only bothers to do that to target actual subjects of interest, and don't have infinite leeway to not produce results while doing it - i.e. if the NSA produces no useful intelligence on Al Qaeda for a few months, they're looking at budget cuts.
Or to put it another way: how many man hours did they expend on this effort, and how many people do they actually think work for the NSA? It's certainly not "millions".
These guys were manually viewing wireshark dumps. Obviously they're going to spend a lot more time to get the same info when working at such a low level, with no access to any of the automation tools the NSA uses.