It doesn't really matter whether or not the people who run the club or concert series are musicians - what matters is their organizational skills, people skills, and their committment to what they are doing. It's hard to imagine that anybody would decide to run (or help run) a folk club or folk concert series if they didn't have a strong interest in folk music, however. There's a lot of work involved and most of it isn't glamorous or particularly exciting - not to mention it's time consuming and often thankless. As for glory or self agrandizement - well running a folk club is hardly perceived by the public at large as a great "feather in one's cap"! Likewise, if someone were looking for a money making venture, a folk club or concert series would not be the way to go about it. Most of these little organizations are barely solvent and there would be precious little left over for "skimming" if that were someone's intent.

Speaking from the American side of the pond, I think the British type of "folk club" is rare here. What you would find would be small coffeehouses or house concert series. I help run a small coffeehouse concert series in Richmond, VA (we have seating for 45). We convinced the owner of a small coffee shop to let us use his premises and he stays open during the concert evenings (usually he closes at 4:00 pm) so he can sell coffee and refreshments (there's no alcohol allowed). I am a musician but the two co-organizers are not. Like me, however, they love traditional folk music and were frustrated that there was so little available in the area. We manage our expenses very prudently and so far have been able to cover all our costs and have a little bit set aside in the "kitty" to cover unexpected contingencies or to pay the performer in case we had an off night. There is another folk concert series in town that has been running for four or five years. They use a church auditorium. There is no evangelization but he is expected to turn over all his profits (after he has paid the performer) to the church meaning he has nothing to cover incidentals and he has had to heavily subsidize the venture out of his own pocket. He is a musician - the advantage being that if he can't find a good opening act he can just do it himself. Musician or non-musician, I don't think it makes any difference. I can't see why a non-musician would want to run a folk club unless the music aspect was important to them.   It may be that it is their way of contributing, even though they cannot participate musically.