- some editor probably
In my handful of encounters trying to contribute to wikipedia it's always been such a frustrating experience.
"not enough people monitoring for quality" is one way to put it, but I've often found it to be one very zealous person monitoring for their idea of quality. It ends up quite frustrating, especially if you're a domain expert.
I've corrected articles where things I've written have been cited and had the changes reverted. It was enough to just give up.