Places relying on tourism as economic activity are very susceptible to economic crisis and it can even go as far as suppressing generation of jobs in other sectors and people leaving because you only find jobs in tourism or you can't afford to live in the city because Digital Nomads live there already. This is obviously exaggerated to make a point, but I think the point still stands in smaller scale.
Foreign money flowing in does not need to be a bonus. DN have the potential to change the microeconomy and in ways that affect your macroeconomy much more than just money flowing in.
Take a place like Barcelona, a famous example for people not being able to live there anymore due to high prices. On top of that, a lot of digital nomads don't interact much with local culture. When people start leaving, is the influx of DN money really still a net positive? Especially considering some of them don't even pay income tax?
I don't want to demonize immigration, but people moving somewhere and treating it like a cheaper version of their hometown is not a positive in any way, culturally or economically.
I am not arguing for socialism by saying that people coming and spending some money (not even that much) is not a sustainable way to do economy. I've got no problem with foreign investors building things that are actually valuable to the economy by building up industry, creating jobs or whatever. Cuba, Venezuela and Argentina have a whole lot of different problems and the reasons they are in the positions they are are much more nuanced than "socialism bad".