Because rude behavior in children is more often the thoughtlessness than of deliberate aggression, criticism, namecalling and orders only make a child angry and defensive.
And, if I may mention so delicate a subject, endeavour to check that little something, bordering on conceit and impertinence, which your lady possesses.
And there are practical problems involved with texting too, as he explains to BBC World Service's, The Why Factor: If you speak to someone in person and they don't respond right away, that would be rude.
If you are during a meeting and you start to pull up your phone and keep texting, even with the people within the room, I think it's pretty would be perceived as an impolite.