The editors argument would work better if they would say: "we donated (time, work, knowledge) and are not happy with how foundation spends its resources (money)". The whole "pay gap" thing is muddying the water. One comes closer to the truth when abstracting donations and resources.

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.