If it's worth mentioning it, a lot of people in both, the english and the spanish chat, usually ignore the NPCs texts as a whole.
People who are new to the Pokemon Games and, for some reason decide to pick PokeMMO as their first, usually simply ask for help to the other players.
And that includes people who are playing the FireRed and/or Emerald Plots for the 2nd, 3rd and so on time, they totally skip the NPCs dialogues and straight say "Now idk what to do, what comes next after /Insert any part of the game's story here/?"
So yeah, if people already ignore the important NPCs, I don't see why most of them would care about the useless ones.
With that said, I do have to point out that they give a little bit of life to the game, because seeing empty towns or cities would definitely NOT be cool at all.
So instead of completely remove them, moving them to places where they don't hinder anyone would be better.
EDIT: I do get that the other users also gives the feeling of things being alive, but when they don't look at all like the other NPCs referring specifically to how everyone has this D/P/Pt/HG/SS sort of design, it just doesn't feel as they belonged to these worlds, while the NPCs do feel like that.