This argument would work better if the editors were paid in the first place, and then they see an increase in the executives' salaries and get jelous or feel it's unfair. Clearly not the case, since they already knew it's all volunteer work.
Edit: Looking at the video with the monkeys two posts up: there could still be a point to it, if we look at the total earnings and total work of a person, instead of just looking at wikipedia: an editor who earns 100k with their day job and donates work to wikipedia can still feel it is unfair when wikipedia management earns four times as much.