Just got around to watching the video finally on DTube! So glad that platform was created.
On the creation of value of out thin air topic, my economics friends and I have discussed this and we can't exactly figure it out either. The best starting explanation I have is that the underlying code is still of value and since the historical record of the chain remains with both, a remnant of that value remains. Now I don't understand why it doesn't operate similar to a stock split or a tax-free spin in the equity markets where a company splits into two and each are valued independently and usually the combined value at the onset is equal to the original whole. Not entirely sure how this is all happening.
One thing that would be great to discuss is whether or not the Ethereum fork will actually spurn a new alt. It appears to me like theres far more agreement with the upcoming fork that a new ETH-alt isn't likely. I could be wrong, but that's my current take.