The expected value of a poker hand can be determined using factors such as pot size, players, and probability. Those are objective measures. Warren is saying that it doesn't apply to bitcoin, because there are no objective measures to pull to come up with a proper EV.
That is how EV works. You can't just say.. there is VC investment in some third party exchanges and more stores are accepting bitcoin, so that means it has positive EV. That's just an optimistic guess... not EV.
Fundamentals(statisticated) and TA could be considered objective measurements. But I don't agree with your opinion that you need objective measurements for EV calculations in the first place.
If I had to purchase a hooker and one would look like you, the other like Penelope Cruz. I would estimate my EV is greater with the Penelope Cruz lookalike. But beauty, hotness,... is not a objective measurement.