I think it makes sense that people who don’t have actual experience in making projects in a specific language won’t be aware of details such as the value 0 being the default in a certain kind of field in a certain language which makes it a good flag for “data unknown”.

The whole “COBOL’s default date is 1875” thing is just a lie. COBOL doesn’t even have a date type.

So the problem doesn’t have anything to do with COBOL, someone just made it up