Last I looked, you couldn't levitate a giant star bear with your heart. So, not useless.

Are you guys deliberately missing the point, or do you just not get it?

Magic is useful as a talent, that is undeniable. However, the Elements of Harmony are based on qualities that are useful to have in a friend. Being loyal to your friends will increase their trust in you. Honesty helps friends understand each other's shortcomings, and can also increase trust in the friend. Generosity makes friends like you, since if you give up your own possessions to benefit others, they will think more highly of you in the light of your donation, and their own reception of the gift. Kindness helps to create a pleasant, uplifting environment for your friends, and will make them think more highly of you. Laughter (Or, to put it better, a sense of humor) will make being with friends a fun and enjoyable experience.
Each of these is a social aspect of someone's personality.

"Magic" is not an aspect of a personality, it is an ability that is either learned or given at conception. Human beings can be friends with each other without our seemingly magical things such as Religion or Technology. Personally, most of my friends are those that I meet outside of my church, or the internet, since outside the confines of our "Magic," their true personalities can properly grow on me. If we did have supernatural powers, they would most likely not be used in making friends.

Tl;dr: Being magical does not make you a good person, but being any of the other elements in a non-extreme way does.