A blind man stands at the edge of a busy street clearly wanting to cross. Other pedestrians crossing stop and ask him if they can help. To each he asks "can you see?" and when the pedestrians answer that "yes, I can" he sends them on their way without crossing. Eventually, a pedestrian answers that "no, I can't see because I am also blind". The bind man quickly grabs the hand of this pedestrian and ushers them towards the road. "great, I feel much more comfortable crossing this road with someone who I have so much in common with!"
We are all blind to something. Nobody knows everything or has such a diverse set of skills that they can look at a problem from all the angles at once. This is why diverse (I will define exactly what I mean by that world in just a second) teams are more creative, adaptive, and successful than homogeneous ones. But in the investment world, this homogeneous approach is what persists: The folks who must make the decisions assemble blindly homogeneous teams to help them make those decisions. The result is predictable... failure.