

This is just avoiding the issue of having a short attention span.
I used to be easily distracted during online lectures yet had little difficulty following live lectures. It’s a fundamentally different experience, for whatever reason.
Also, the attention span has to be trained. And training it by working without a distracting computer sounds like a good idea.
What surprises me isn’t that AI failed, what surprises me is that Zuckerberg believes in his own hyping of AI so much he had the confidence to try to do this at all, live, unstaged. Is this courage, honesty, stupidity, hubris?
The most favourable explanation I can think of is that they tried it out ahead of the presentation, it worked well enough, so they trusted it could be repeated.