I believe that everyone strives to be kind throughout life. Despite how some behaviors may seem, the individual behind the action may have the perception that they are doing it with the best intentions. Unfortunately, kindness is valued differently by everyone and the receiving end may not align with your own morals.
Better is to strive to be sincere. Being genuine towards others and in your intentions mitigates that potential for misunderstanding. Listen to what is being said and speak straightforwardly, with honesty and from the heart. Often this can mean that you will have to be unpleasant in your words, but by understanding that you can help them be receptive to it while still grateful for your frankness.
Nothing exists in such black and white absolutes, and life is no exception. Better to be sincere than disingenuous.