It's certainly possible that they stole the bitcoins and paid for a few days (a week?) worth of goods.
But 1) the article does not provide any real evidence to support for this theory, 2) it's not a sufficient amount to be a viable strategy, and 3) the evidence even linking the thefts to NK sounds somewhere between non-existent and very flimsy.
When the FireEye report's leading point states: "...there are no clear indications of North Korean involvement", it's not good support for such a broad statement as the title of the article.
Again, it's definitely possible, but too little information appears to be available to draw this conclusion.
There are that many people, but I suspect a much, much smaller number of people actually benefit. The overall population probably isn't all that applicable.
Imagine going long - very long - with a stash that big.
The pundits-in-the-know often semi-seriously state they expect 1 BTC to rise to $100,000 USD within 10 years - looking at the past 5 years that's not an unreasonable statement to make. This is based on BTC's deflationary nature, and its increasing prevelance in the world. Imagine if you owned one 28,000,000th of the Internet economy - that would still be a lot of money. What if you owned 10x or 100x of that? In BTC it's still an amount affordable by a large organisation or nation state, but in 10 years' time it would be like having your own Fort Knox.
That's an oxymoron. And I'm not even trying to be cynical. People in-the-know aren't pundits, they're the ones the pundits are talking about. You can tell because pundits suddenly have alot less to say, and are much more circumscribed, when they're discussing topics with which they have contemporaneous, first-hand knowledge--pretty much the complete opposite situation of someone publicly predicting the USD price of BTC 10 years down the road.
$100,000/BTC isn't a raw extrapolation to my knowledge and I've been in the crypto space since early 2009. It's a popular number chosen that'd represent BTC @ ~1/4 the market cap of Gold.
Which I don't think is that unreasonable if you're evaluating it as a store of value.
[1] https://en.wikipedia.org/wiki/Economy_of_North_Korea
[2] http://www.indexmundi.com/north_korea/economy_profile.html