No one treats the comma as a decimal point. I think the OP just misread it...
According to Wikipedia a heap of countries do:
SI style (French version), Albania, Belgium, Bosnia, Brazil, Bulgaria, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Latin Europe, Lithuania, Netherlands (non-currency numbers, see below), Poland, Portugal, Romania, Russia, Serbia, Slovakia, Slovenia, Spain, Sweden
There actually seem to be a bug in the WP emulator when emulating GPS in countries that use a comma, for example if I switch to French the emulator no longer reports any GPS events.