because the poor people can't move $10 around without paying $3 for it. Have you ever tried moving small amounts of money in poor countries ?
Many have speculated he may be a time traveler, although they don't give any reason. The only thing I can think of is he possibly traveled back in time after witnessing a massive economic downturn that had people eating rats off the street and an even further (much more serious) dichotomy of rich and poor. Bitcoin could level the playing field stopping banks from having nearly full monopoly of your money.
There’s no way it’s then suddenly a cost effective way for normal currency billionaires to move money around. Converting that amount to BTC would require serious fees and resources.
So this point is largely moot to any wider discussion.