Back in the day, when I was first appointed (prematurely ) to the BOE there were a bunch of elders that were indeed smart. They had intelligence, worldly experience prior to becoming dubs, and management ability to handle the cong. We had a lot of laughs among ourselves, the meetings were often fun too.
As time went by things changed. The Borg became more controlling and the newer elders were born-ins who could simply follow rules. Often tbey lacked gbe ability to think on their feet so meetings became dull since they could only say what they had prepared. Often they lacked confidence, that is why I can well believe tbe experience given by 'Mum' earlier about her elder husband.
So, "Dumb?".....that is a simple stereotype but to say they lack good judgement, self confidence, teaching ability and tact would certainly be true.