I use them, 31 year old male. Really only the basic ones, and on occasion. The majority of Apple users my age or older, have pretty much bought into the Apple ecosystem, and that likely isn't changing although many threaten to leave. Apple needs to hook the younger crowd, and they like emojis. Makes sense.
I do. I love them. They help convey and reinforce emotions better than text alone could. And they just make texts a little more fun and lighthearted.
One thing that I do NOT do, however, is use the replace-words-with-emojis feature that is new in iOS 10. I'm not about to start using emojis in place of words. I'm not a barbarian. 😛