Equestria Girls has a problem. It's Tenchi Muyo! without Tenchi

I just saw Forgotten Friendship. And once again, the plot is the same: an Equestrian Maguffin was banished to the EqG realm; ergo EqG has to deal with the problem Equestria wouldn't/couldn't handle. Before you say, "that's just the Equestrian Girls' plot gimmick," let me tell you that another franchise suffered for repeating this same plot over and over and over.

Since I assume that the few anime fans here have hardly watched any series pre-2010, let me explain. "Tenchi Muyo!" was one of the earliest of the harem genre, with the original OVAs created in the early 90's, followed by 2 TV series, 2 movies, and 60 minute "movie" that feels more like an OVA. The protagonist, Tenchi Masaki, is an ordinary Japanese teenaged boy, who just happens to be the heir to the throne of the planet Jurai. Why? Because his grandfather didn't want to deal with the political intrigue, BS, (and if we believe the 1st OVA series... the incest), decided to abdicate, and flee to the furthest planet in the galaxy (Earth). The conflicts of Jurai continually show up in front of Tenchi's doorstep, and he and his bevy of alien female friends have to clean up after mistakes and sins of the Jurain royalty. Seriously, let's compare plot summaries of the Tenchi Muyo series and movies, and the EqG movies.

Tenchi Muyo in Love (1st movie) - Most evil criminal in the galaxy escapes after a 200 yr imprisonment. He decides to get revenge on the descendants of the Jurian royal family, since the Jurain emperor led the coalition that captured him. The twist is that he decides to go back 30 years to target Tenchi's mother when she was a teenager. (Don't ask why - never question the logic of a time travel movie).

Daughter of Darkness (2nd "movie") - A Juraian demon that was banished 50+ years ago just because she befriended Tenchi's grandfather when he was a child. Despite having hundreds of monitors in her lair, it takes her that long to find the prodigal heir and his grandson on Earth. She wants revenge on him and Tenchi even though the former didn't want to see her banished, and (of course) Tenchi had nothing to do with any of it.

Tenchi in Tokyo (2nd TV series) - The plot twist (this is a two decade old TV that was pretty terrible - I'm not gonna give Spoiler Alerts) is that the girlfriend Tenchi hooks up with in Tokyo, and dumps all the other characters for, turns out to be a puppet for some lady that has a grudge with the Juraian royal family. So she decides that the best revenge is to target planet Earth instead.

Now for Equestria Girls:

Rainbow Rocks (2nd movie) - It turns out that our villains were originally sirens from Equestria. So Starswirl and the Pillars decide that instead of defeating them (I mean, come on, you outnumber them 6 to 3, or 7-3 if you count Stygian), they banish the three to the EqG realm.

Legend of the Everfree (3rd movie) - The movie's Maguffin is a bunch of geodes from that transform one of the camp's owners into a monster. The geodes had Equestrian magic infused in them. (How? By magic, silly). I'll give this a pass since no pony purposely used magic to enhance theses geodes.

Mirror Magic (3rd TV episode) - an Equestrian mirror falls into the hands of our antagonist, Juniper Montage. It's never explained how the mirror got from Equestria to here, but based on the series' track record, it probably has something to do with either Star Swirl or Clover.

Forgotten Friendship (1st TV special) - It turns out this special's Maguffin, the Memory Stone, was banished and buried from Equestria to the EqG realm by Clover the Clever because it was too powerful. You know, instead of, say DESTROYING the damned thing?!?

I'll give the first EqG movie credit, at least Sunset Shimmer was proactive, and stole the Maguffin, err, crown from Equestria, and brought it over to the CHS.

tl;dr - Ponies be lazy. Even their laziness is ripped off from another franchise. Humans do all the dirty work.