That's like asking why dancing instructors teach people to dance, or swimming coaches teach people to swim. People have hobbies and interests, and go to others to gain knowledge. They cannot make you a great investor, but you can learn from them and become a better version of yourself in that field. TA is rewarding in and of itself... if you invest $1 or $1,000,000, it's being able to maximize the profits that gives you a rewarding feeling...