I do not know if franky's calculation is true, but if it is true making around 600 dollars a day is not really a big number for a nation, don't get me wrong it would make me super rich lol, nearly my salary in 2 days, that's a great thing for a person but that doesn't mean that its a good one for a nation. To be fair El Salvador is a poor nation so maybe this isn't so bad for them, it could be about 20k a month and that's a good thing, plus its a volcano powered thing which is always good thing because it shows the world that we could definitely do it and that's an improvement. All in all this is a good thing, not a great thing, not a huge thing, but its definitely a good thing. We need to keep it in mind as much as we possibly could and be happy about these things.
Well, I personally might not agree with your input stating that $600 per day for a nation like El Salvador is too small, and besides, Franky didn't say $600 per day, he said $2100 per day, but even if the nation is making $600 per day as pure profit from mining bitcoin, it is still something considering that the mining is not the only source of income for the country.
At least, we know for a fact that the nation, El Salvador have existed far before bitcoin came into existence, so this simply means that they have been making money through and from other sources which they run the country with, so right now, if with bitcoin, they now have the ability to make up to $600 per day, combining it with their several other source of income, it is something for sure.
Overall, i must commend the effort of the El Salvador in bitcoin adoption, they have proven and shown the world that their mind is made up in their quest for bitcoin adoption, i hope that one day, they can be counted among the richest countries in the world with the help of bitcoin.