This line of reasoning is founded on a false premise: namely that the moderators who are not financially compensated get nothing out of performing the duties as

This line of reasoning is founded on a false premise: namely that the moderators who are not financially compensated get nothing out of performing the duties associated with their role. On the contrary, the endless supply of willing volunteers for the task suggests that they do get something significant out of it. I would suggest, to start: ego validation, feelings of personal power, and most importantly the ability to skew discussions in order to support one's desired viewpoint. I would suggest, additionally, that the last listed reason is a significant source of potential bias in moderation, in view of the fact that the value proposition of being a moderator is very appealing to an unrepresentative subset of users of a service. Furthermore the financial value of being able to do this is far greater than a typical paid content moderator wage.