As a former brony (there, I said it): The show is fine, it's a tiny bit of escapism with decent writing, funny characters, neurotic "girly girls" (even if they come in pony-form) and used to be nothing but a guilty pleasure in the same way people watch Adventure Time or Gravity Falls.

The fandom only started to take a darker turn when some outside criticism and trolls started to imply an underlying sexual aspect that absolutely wasn't there before. MLP was about escaping a lonely and at the same time sexualized world into a world of innocence. But like with all things obsessively online, part of the brony fandom ran with it and new people arrived in the fandom drawn explicitly by those rule34 aspects and they brought a very 4chan-and-furries-vibe that absolutely caused me to leave the fandom behind.

Most of the OG bronies retreated into safe spaces like closed servers or just watching the show without gushing over it on the net as to not look like those new icky bronies and that largely spelled the end to a formerly very innocent, colorful and accepting fandom.

I'm not sure I can be on board with that one because that show was actually pretty smart and funny. I think the performative semi-ironic macho rabid fandom, maybe, but if you ask me that was just extremely postmodern shielding of insecurities.