Well, I could tell you why, even though its not the very best out of the others commented on this. I, too, am a fan of the show and this great community. Its known as "Becoming a Brony," if you watch the show in general.
Becoming a Brony:
1. Denial: Its a little girl show, why would I bother watching something as girly as this.
2. Anger: WTF IS THIS, I REALLY DON'T UNDERSTAND WHY GROWN MEN WATCH THIS COMPLETE TRASH!
3. Bargaining: OK, the show holds great writing, great characters, funny humor, and dark moments. I think I should watch more episodes, just to see more on my research.
4. Acceptance: OMG, I LOVE this show a whole lot, I just LOVE being a brony from the bottom of my heart, I just wonder what friendship could be. *singing the opening theme of the show*
So, these are the steps of becoming a brony in general. What I do is advice all the trolls and haters on the show: Watch the show before you judge. We aren't hurting anyone in general, we just enjoy this show from the bottom of our hearts, and love it to death. We, bronies, have this very important saying, "Love and Tolerance to all the haters and trolls everywhere."