>>101449908>It began as an ironic thingLook, I know being ironic is a hip and cool thing to do nowadays, but let's not change history. When MLP came out, the love for it was an honest thing. The show had a stable general on /co/ for nearly an entire year before it got big.
Someone's already listed the reasons MLP got big, but I'll reiterate:
The novelty of MLP being good was a terrific springboard for getting people into the show. Pic related is a guy talking about why he got into it.
The timing of the show was perfect, because there had been a slum of good cartoons the years before; with only Adventure Time really sticking around in any real measure.
I personally believe that the setting of the show played a part in it; in that serious fantasy is just something we don't get anymore, but that's just me.
The production qualities, writing and design and such, were legitimately good, but that plays into the first point.
And of course, once the fandom established itself, it became an 'identity' that losers attached to; which only made the show bigger when the internet began to lash back at them.
I'm certain there's dozens of other reasons it got big, because it was simply just lightning in a bottle and that requires everything to be perfect, but that's the gist of it.