You know, I can't help but think that perhaps certain types of leadership don't require intelligence. I was having a conversation with a coworker today (in my government job) about the politicans who run our province. The vast majority do not have any college education and many are severely lacking in the intelligence department. Yet they are in these positions of power and influence (and earn big money). Maybe it has something to do with being easier to control?
Perhaps the notion of elders not being bright appeals because it's so hard to fathom anyone with intelligence embracing the party line to the degree they do. I found most elders were of average intelligence, simply uneducated - and I agree with 00Dad. In the context of DFing, I've seen some very small, vindictive men, as LadyLee has. Those seem to me to be men who don't have the intelligence to succeed anywhere else, so they get their jollies power tripping on the lowly rank and file.
There are always exceptions. When I was young I recall one very intelligent elder who always advocated against the no-university policy and he was not very happy with DFing either. He was often on the outs with the other elders, though, and I think he'd be in trouble if he were still around today. Then there is my brother, who is extremely intelligent, yet falls into the category of "vindictive small-minded elders".