Earlier quoted context omitted.
You must be American then because that's the American format. Different countries and languages have different format of numbers. That's one of the most common issue in internationalization. If you send a bill for a 5,000 dollars service, expect your international customers to send you back five dollars. The comma is broadly interpreted as the decimal separator.
I think it's less to do with country and more to do with language. All English speaking countries use the comma as separator, and the decimal point as the decimal separator. So, if you're reading an article that is written in English, from context you know that decimal points will be used as decimal separator and comma will be used as digit grouping. No confusion. However, confusion happens when non-native English sp…
American English is not equivalent to Australian English or Canadian English.