I hate how hipster I am about kale. My ego needs people to know not only did I grow up eating kale, but as an adult I’ve loved kale since my first daughter was tiny; about 10+ years. I got my (original) bumper sticker then, too.
The reason I love it is pretty simple, though the list is long, too:

• absurdly dense nutritional value
• can be grown year round – no kidding (sweeter when it’s cold)
• *super* cheap
• soooo easy to grow
• amazing range of ways to cook and eat it
• tastier and easier to cook, more versatile than collards and also more versatile than chard

For me, the bumper sticker means that if everyone ate more kale—especially if more people grew it for their friends, family, and neighbors—the world would be a better place. We’d be healthier; the planet would be healthier; and we’d all save money.
Eat more kale.