Joe Armstrong is the co-creator of erlang, so I'm pretty sure he knows why programming is difficult, he's just being personable and cheeky in this essay.
He's also got a habit of asking why and finding out (keep in mind by training he was a physics PhD), this essay notwithstanding.
You were commenting on the persona, but also stated "Im not sure he understands why he's finding it so difficult."
If you believe the statements he was making were rhetorical in nature, but are dismissive of them, while also crediting that as an individual he was insanely intelligent, with both a level of experience and a level of curiosity that outshines most of us...perhaps you missed the points he was making?
He's also got a habit of asking why and finding out (keep in mind by training he was a physics PhD), this essay notwithstanding.