My honest opinion of the MLP phenomena is this.
Pre faust MLP was just about the most godaweful show in the history of childrens cartoons, and i remember back in primary school (grade school for you filthy american pigdogs) that if you wanted to insult someone, you would doodle his books with crude mlp drawings (this was before we discovered the noble art of spamming cock drawings), and the one poor sod who was forced on one sad day to take a MLP lunchbox to school was ruthlessly mocked for years afterwards, it was even considered an insult to the girls if you implied they were fans of it. It was worse than barbie, worse than....whatever other shit was targeted at girls, it was literally the bottom of the barrel.
Lauren faust took this abomination and turned it into something that was...pretty ok for a kids show and which had agreeable amounts of non-idiot humour for non kids to enjoy. The kind of show I would have happily sat kids down to watch while babysitting them and not have my senses offended. This contrast between the filth that it once was and the well above average show it is now I think shocked many internetters, and caused an instant fandom to arise, partially out of genuine affection and partially out of the ironic humour of "ZOMG MUTHERFUCKING PONIES ARE AWESUM! WOO BRONIES FOREVA!!" which tends to arise when aggressive macho internetters find something cutsey and adopt it for laughs.
However this fandom then attracted the usual suspects of tardom and fail, the melodramatic, the lonely, the desperate, the degenerate, the shipper, the "serious" fanfic writer, the fapper. These types took away the inherent lack of seriousness behind the fandom, and in its place put the same loathesome sincerity that so corrupts the fandom. In place of the netter who called himself brony for laughs after watching an amusing remix involving ponies, is the melodramatic fuckwaffle who will tearfully defend their one true fandom in essay length posts of hour long videos.
Sure the small core of sane fans who actually just find they enjoy the show on it's own merits without "LOLROFLMPONIES" or "FUTASHY IS MY WAIFU" playing into it remains, but until the spergs find a new breeding ground the show and the fandom as a whole will remain forever tainted by association