Worth noting that that is normal in some non-English-speaking localisations. Indeed, you can see the dot rather than comma for the decimal grouping separator on the Fans field.
I agree with SamBC.
The developers are based in Australia and Austria, both of which (Thank you Teelo) where Austria uses a comma for decimal separator, and period for thousands separator. (According to Wikipedia) Therefore if the game information pages default to showing this, its fine. I know when I play, the game properly uses my localization for the United States (Period for decimal separator, and Comma for thousands separator).