In any case, defaulting on debt is completely natural. It is what's part of how the system is supposed to work. If lenders didn't pay attention, out of lack of knowledge or willfully, and the debtor cannot repay, that's it. There has been a very successful campaign that strengthened the side of the lenders, big and small, over many decades - not necessarily consciously and deliberately (not a concerted effort). It's been successfully made into a moral issue.
The (most likely German) authors of that map forgot about the existence of their neighbours to the West - the Netherlands are a blank void, same color as the North Sea.
Also, most of these nations defaulted because of vast political and societal changes. (russia has defaulted many times on it's debt thanks to the soviet revolutions and dissolution of the USSR for example).
Most countries in the world have had sovereign defaults, often several times throughout their history. See, for example, the map at https://katapult-magazin.de/en/artikel/artikel/fulltext/ston...
Spain defaulted 9 times, Portugal and Greece 6 times, Germany 5 times, the UK 4 times. They still get loans now.