Are you a male that feels under-represented in My Little Pony? Inexcusable! Culture War Reporters has a short blog published that discusses a tumblr which purported “misandry”–that is, inadequate representation of males–in the show full of ponies. The original tumblr hosting these ideas is now gone, but another article by the same name (My Little Pony: Misandry is Magic) may have a point in saying that male representation is lacking in the show (not something the blog author is promoting, I clarified). Then again, the guy (or girl) who wrote the article may also be excluding information to prove a (bigoted) point.
Spike is a baby dragon, not a pony, plus he has a minor role in the show, thus he cannot be considered as a main lead.
But who are we to judge?