They intervene because they are worried on what will happen on El salvador if major collapsed happen and we can't deny that this events always happen every year. And I can't also blame other country be worried about them some goverments in other big countries doesn't believe the potential of bitcoin so maybe this is a good wake up call to other nation that if this country became successful when adopting bitcoin then maybe this will be their basis to adopt it on their systems.
If a financial collapse occur in El Salvador, then they the other nations need to worry about it? Latin America is full of failed economies such as Venezuela and Ecuador. And in none of these cases, cryptocurrency was involved. If a financial collapse occurs in El Salvador (although there is hardly any chance of that occurring), the Salvadoran public know how to deal with it. The so called neighboring countries should worry about their own economies first. From what I can see, they are not doing that good.
I believe that in a worldwide collapse of the economy, El Salvador would have much more lifebuoy thanks to BTC, the reason is simple, history has shown us that each collapse of the economy, as in 2008, always causes great losses for those who do not take advantage of the crash. , the economies of South America also enter a collapse, since most are ruled by the dollar according to its hegemony, most countries do not have a corresponding stability.
If a Country like El Salvador manages BTC, its citizens who have savings there becomes an investment as good as gold, because its price will tend to rise, and those who have investments in Gold, BTC and Real Estate would not have any problem or the crisis would affect.