Actually, my working theory is that the general public HAS figured it out.
You and I have the same tools as the big guys. One thing we have that they don't is a sense of paranoia. This guy had a non-government email and either jumped a phishing link or had predictable two-level secret questions guarding the gate.
Having hacked into the "freemail," the hacker examined the contents for clues and hit pay dirt on an exploit or took advantage of reused passwords.
I am not a hacker and neither are you, but we could be. It's not hard work to move from where we are, technically, to that skill level.
There are many more people outside any governments than there are on the inside.
The theory of probability and statistics implies that there are smarter people among the masses than there are smart people working for the government.
We're all using the same machinery, the same skills, the same software ... it's a level playing field and everyone has a gun.
Some of us just don't load up.