I thought Obama showed a ruthless streak when he swatted that fly. I'd have captured it in a glass and let it out the window. There was no need for him to kill it. It displayed thoughtlessness and a lack of respect for life and the wonderful process of evolution that has produced flies. I don't agree that it's 'just a fly' so doesn't matter. Everything matters, but to varying degrees based on ones own perspective. If it had been a mosquito biting his arm, it would have perhaps been justified, but a fly just buzzing around? Death was a little harsh I think.
The point about being kind is that it's an attitude, not an action or combination of actions. It's all about precedence. If one can be unkind for no good reason to other things (whatever they may be - even inanimate objects) then one can use the same argument to be unkind to other people. It's a road to psychopathy!