[deltaonethree]

I actually don't know first hand. I only heard it was easier and thought it was a well known fact. Thanks to your comment I think it may just be a popular myth rather than a well known fact.

Either way if you're saying the "hardness" is the same, the conclusion still stands. "Hardness" is not the metric that is making European quality of care better than the US because both countries have the same "hardness".