But the point is that this fandom tends to make assumptions based on such coincidental details. For example, how many fanarts have you seen portraying Derpy as being obsessed with muffins on the grounds that she said the word muffin in one episode, and not even being the only character in that scene to say it?
When we saw Rainbow Dad in Rainbow Dash's flashback (Season 3 Episode 12), his eyes were gold like Derpy's, a very different color from Rainbow Dash's eyes. But the picture is more of an observation on how the fandom makes huge assumptions based on very minor details, such as the idea of Lyra having a thing for humans because she was shown sitting like a human one time, or Derpy being obsessed with muffins because she said the word muffin once.
The sad part is, I actually have seen it. I just didn't notice her Dad there, and I this was the fan's interpretation of what her Dad looks like that they decided was official rather than headcanon Boy did that link shut me up...
That makes sense. That being said, they could have made Last Round-up funnier by not having her destroy Town Hall but by having her complain about the rainbow-maned embarrassment of a cousin she has to call "boss."
I think makes more sense for Dash to be annoyed at having to work with he "weird" and clumsy cousin. Derpy isn't the sort of pony to who would look up to Dash because of the other mares flying skill and her being a element of harmony.
I agree that Derpy is much better when her only "problem" is her eyes (although i do think a little aphasia/word salad disorder is okay) and i like fics where she is very intelligant as well as tech savy (being the companion to a pony time lord will do that). That said Derpu stealing from Carrot Tops fridge or being a master thief (of Muffins!) is really funny.