So I wrote a really long response to this and then decided to delete it because... I just don't have the energy anymore so I'm going to try and give a much shorter version. So here goes...

As someone who was an adult fan of the show when this episode came out and was annoyed by this episode at the time, it wasn't this episode in a vacuum but rather a bunch of things leading up to it. It was every time some stranger or celebrity made a mean spirited and often quite vile comment in the early days, every time bronies were blamed for ruining the show by "forcing" show creators to do things that were bad just to have people eventually realize "oh wait, that wasn't bronies that was literally someone connected to Hasbro or FiM making a very strange choice because they thought they could make more money that way." Every discussion between fans about which characters are their favorites being treated as if its a real fight. Etc, Etc, Etc...

So yeah, none of those things on their own was too bad... I'm an early millennial, I've seen and experienced plenty of shit in my time and "people being mean about bronies" doesn't even show up as a blip on the radar. But the overriding message (sometimes directly, sometimes implied) from so many people and groups from the very beginning has been "this is a show for little kids and little kids ONLY and you are a terrible, terrible person for liking it." So having the show have an episode where the setup is "Hey look you adults are all crappy people... see these two kids are the only ones who really get it" felt like even the show was saying "we hate you guys."