My Little Pony XIV: Boots on Hooves / Bikinis on Top

[TheAmishPirate]

So, I've heard having OCs in fanfiction, shipping or otherwise is bad. Is there a specific reason for this other than that OCs can tend to be Mary/Marty Stus?

That's probably the main reason. Without having an established character to work with, it makes it that much harder to write them well. As a result, you get a lot of stories with OCs that are just downright awful.

There's nothing wrong with it, it's just a harder thing to write. I mean, just look at Moonlight over Midnight. 6 stars, and it's mostly about an OC.