You do realize that hunters titans and warlocks can be human, right? Those are classes not races. I get what you're saying though. Why would real people identify as being something that they aren't? The answer: laziness. "What class do you play as?" "I play as a hunter." "What are you?" "I'm a hunter." The second conversation, while not necessarily being accurate, (unless you're Ted Nugent... then you can say with full confidence and accuracy that you are a hunter) is just plain easier to say. When in a situation between people who have a mutually understood context, it is common for people to circumvent proper syntax because further clarification is unecessary. Example: (asked of a Destiny fireteam member) "What are you?" "Well there are several ways to define what I am. By species, I am a human. By trade, I am an accountant. I'm also a father and husband." "No I mean what do you play?" "Oh, I'm sorry I didn't know what specific context you were referring to. I play Destiny, GTA 5, The Witcher 3, Monopoly, Trivial Pursuit, Angry Birds...' "That's not what I meant." "Oh I see... well, I play piano." And so on and so forth. That just seems silly now. When we are logged in to Destiny, or on a Destiny forum, we share a mutually understood context. The context is a fantasy space magic video game. So when someone says "What are you?" the answer is given within that context based on assumptions about what the most pertinent answer is in a given situation.