not enough sympathy
c.1300, "state or personality to be unkind, not enough all-natural regard or proper consideration," from un- (1) "not" + kindness (n.), or from unkind (adj.) + -ness. Indicating "an unkind act" is from c.1500.
The ancient cannon, which look seaward, wear a very menacing expression; but I doubt if there is any unkindness in their rusty old hearts.