Valid point(s). Admittedly, I didn't read the entire thing. I just wanted to see who pointed out the error and who threw a fit over it. I wasn't disappointed.
In virtually all contexts, a comma acts a break in a continuing statement. A period denotes the end of a statement. That this concept is reversed in many countries for currency is an anomalous exception, not the rule.
So while it would be "ignorant" to not make the distinction while in a European country or discussing European currency, calling an American "ignorant" for not making the distinction, especially in the context of US currency, is just being cunty.