I plead plot bunny.
Sometimes you just have to get the new idea off the top of the hopper in order to let something else through. And in this case, the idea was 'What if R. Lee Ermey met the Mane Cast?'
...look, this is how a writer's brain works. You think of something and then have to come up with some reason for why that idea is not utterly stupid. In this case, it started as a comedy, right up until I realized it wasn't. Because this is way back in S1, during the days when -- let's face it -- Harmony hadn't quite managed to solidify. The episodes of the first season have their moments where the group is trying to find its dynamic, or even recognize why it's holding together at all. It takes time to close the last of the gaps.
In fact, this didn't even start as a 'verse story. It was originally going to be more towards general access. But around the same time the Comedy tag came off, I realized it was better off serving as a look at those first days, and six mares who weren't entirely sure how they all felt about everypony in the set. And so it wound up as 10k of flashback, and while I hope there's a few laughs... the Comedy tag wasn't justified. It's something else entirely.
You think of something, and then if you're lucky, your mind lets you know about all the thoughts which were waiting underneath.
Writers are weird.
You knew that.