I think we've pretty well established the stigma against My Little Pony has its root in sexism and belief you have to grow out of things. Not sure what else to say.
Therefore we can agree this has been talked in circles
As bad as the Being fandom can be, I would never wish it didn't exist. I (for the most part) got into ponies, via the nicer side of the fandom. It wasn't perfect even then, but it was better, and the fandom really needs a lot of work, but I'm still glad it exists, because I have fond memories of when things were nicer.
Also, the term doesn't really exclude women. In my mind, and in the mind of some others, it's a unisex term. I know it probably started as "bro" and "pony" but it just became its own word, and became genderless in my eyes. Anyone who wants to be called a brony, is a brony, regardless of their sex, in my opinion.
EDIT: Sorry, didn't see the off topic warning.
And with ignoring the warning I am going to lock