Because it’s only (maybe) a good design if it’s to be read by a human but that’s not a very general case. Instead people unknowingly make for example some expor

Because it’s only (maybe) a good design if it’s to be read by a human but that’s not a very general case. Instead people unknowingly make for example some exporter for a text format and write code that writes "X={x_coord}" and it passes all the unit tests and all the acceptance tests and then it breaks once it hits a French or scandinavian machine. A great example how bad it is would be that the C# compiler repo for a very long time had tests that failed for everyone with non-US formatting.