[CodeMage]

It's just my theory, but after 12 years here I haven't found anything to replace it.

You see, the vast majority of homes use tankless gas water heaters. I'm not sure why, maybe it's the most efficient or most economic solution when your primary source of heating is gas.

Whatever the reason for, it's the reality and one consequence is that nobody likes to keep it turned on for longer than it's absolutely necessary, both for safety reasons and to avoid racking up the gas bill. So everyone is simply used to washing their hands with cold water at home. Since that's what they're used to at home, they don't expect anything different anywhere else.