I find it odd how women are always the last get the kindness.... its like kind is some kind of a pie but we aren't going to get any.
'Be kind' is essentially a command to obey female socialisation. This is why it is not often said men, since they rarely stop seeking a goal or change direction out of guilt or sense of responsibility on hearing it; it doesn't have much effect on them or meaning for them, and isn't expected to. It is expected to redirect a woman, and imply there is something lacking and wrong about her if it doesn't.
Female socialisation means: put others first, serve others first, mummy eats last and least after everyone else's needs are met, and good women do this without mentioning or complaining about it .
'Be kind' means essentially in this context 'be good'. Where 'good' has a very specific meaning. It's rather like other buzzwords thrown about such as 'diversity', 'inclusion', and 'intersectionality', where the point is attempting to gain compliance from others rather than reflecting any real integrity based belief in the value itself. And in all those words, it is always one way only with an expectation that this should be accepted as due to some but not to others. It is a world view that tries to separate the world into the served and the servers.