I started thinking about this (which is not actually as rare as you might think) because someone thanked me for being "really kind" not so long ago.
Had I scooped this person out of the path of a car? No.
Had I pulled this person to safety after being about to fall off a cliff? No.
So what had I actually done?
In actual fact, this super amazing kind thing that I'd done was send this person some words of support as said person was struggling through a severe depressive episode. I consider that basic decency more than anything else, but that might reflect what I consider to be really kind - which requires doing a supererogatory act (in layperson's terms, something that is above and beyond what is necessary). I do not consider kindness above and beyond what is necessary, because firstly it's a very basic comfort that anyone can give and secondly, it doesn't require anyone to go out of their way.
it may actually make you feel better (that said, I would not trust that abstract too much) - either, and it makes the other person feel better. To spell it out for you again, it costs nothing, it takes very little time, it doesn't hurt you and the other person profits.
So what the fuck is wrong with us as a society that we're so unkind? It's a tiny little thing that anyone can do for anyone else, and we can't even manage that? In fact, sometimes I think we look for excuses to be unkind: they deserved it, they're just looking for attention, it's not that bad, I'm late for work already or I don't want to read their stuff so I can just politely ignore them, I'm sure you can think of many others...We get our pleasure out of hurting people - how do you think bullying works?! And for some reason, the thought of extending kindness to others scares us (that's the conclusion I've come to, anyway, what with people making their various excuses). I don't know why this is; I'm no psychologist. The best I can come up with is that we see happiness as a finite commodity and don't want to share, especially not when we feel pressured into being completely happy all of the time - which is what happens in a culture that extols positive thinking, positive outlook, positive fucking everything. You practically have to shit joy for this society to accept you, at which point you're lying to yourself, deluded, or completely psychofucked out of your skull, but that's another rant for another blog post.
If we all did that - if everyone took just five minutes to help someone else out - there'd probably be a lot less suffering and pain in the world.
And if that didn't convince you, I have one last thing I can probably say to you. I hate to pull this argument out, because it's hackneyed and manipulative as all holy fuck, but you probably think that bad things won't happen to you. It's a well-known cognitive bias. Most of us think that way.
That's secondary to the main point, though, which is that you will want even just a hug for some kind of emotional sustenance. And of course, people will do what you did - which is make excuses and walk away. Most likely you won't think that's fair, because human beings are generally a bit shit and inconsistent like that.
If you deserve kindness that badly, why not them?