Ok, so here's a thought. Early on, Pinkie says she knows everyone's name in Ponyville. We find this to definitely be true.
However, later on, we see each of the Mane 6 calling a lot of background characters by name, and never seeming to not know someone. That's fine. Other than Twilight, it makes sense, given they've lived there a long time. Even Twilight could have learned everyone's name.
But then, we see situations where it seems like they don't know everyone. In Hurricane Fluttershy, we see a ton of characters treating Fluttershy like shit. Now, given the community nature of the town, one would assume they know her and know how she is. So either a LOT of people in Ponyville are jerks, or the show has given a wrong feeling about the town. This doesn't even go into the fact they should be the most well-known ponies in Equestria after taking out Discord. So everyone SHOULD know them, but even still, they should know at least everyone in Ponyville.