As a personal favor to me, would you be willing to go easy on YouAreHere?
I don't think she meant anything serious or insulting by the "hand-shaking remark;" she was sincerely just trying to lighten things up in the midst of an increasingly heated topic.
I think we can all agree that once one's hands are washed with soap and water (dried too would be nice), then it's perfectly safe to shake that person's hand (right or left). The only exception would be if they had been handling some kind of radioactive material or something.
I don't think YouAreHere was propogating any kind of stereotype; if anything maybe she was making fun of the existence of a stereotype. I definitely don't think she was making fun of you. Not how she meant it.
I know I am using my own interpretation here and Lord knows I've been wrong/mistaken many-a times in my life. But I'd feel comfortable making a rich bet on the probably that YouAreHere's whole post consisted entirely of horsing around and having fun. Even if you feel her joke was in bad taste, please cut her some slack and rest assured she didn't mean to give you a bad time.