Actually, I agree with him/her. Using decimal points where commas belong, and vice versa, is an insanely stupid idea. People (and countries) who promulgate such ideas should not be encouraged. It's just begging for a Mars Climate Orbiter-type disaster.
I reeeeallly don't like it when I have to think about whether my bench multimeter is reading 115 volts or 115 millivolts.
This is a localization (localisation?) issue: different locales have different conventions. It is important to decide on a standard on, say, a project. In the case of an international forum like HN, it makes sense to ask for clarification when necessary. Even if a convention were added to the FAQ, there will always be those who aren't aware of the convention. Cut each other some slack, at least until the HN community decides to launch a satellite.
The thing is, though, the period was in use as a decimal point for hundreds of years, since the time of Napier and Kepler. And then someone in Europe decided to start using commas because, hey, why not, it's cool and fun to be different for no reason.
I reeeeallly don't like it when I have to think about whether my bench multimeter is reading 115 volts or 115 millivolts.