If I may, I’d like to add one aspect of genuinely kind people: they somehow find a way to make you feel you’re kind, too, even when you think you’re not. It’s actually not a new point but an example of what you wrote about such people looking deep into who you are.
And kind people, by definition, don’t have flaws if we’re just focusing on their kindness, much like biblical angels can’t be blamed for their halos and wings. I guess the flaw, or rather the potential problem, of interacting with a person generously giving kindness depends on the receiver’s own response to it. Do we blame the sky for being beautifully blue, or the sun thawing us on a freezing day. If we’re feeling rotten and cynical, no azure sky or warm sun can immediately change us unless we start reprogramming ourselves to have a positive mindset. The sky and sun do what they do. All we need to do is give thanks. And smile for extra measure. :)