A paucity of diverse ideas is intrinsically a paucity of ideas, period. As a general rule, the suppression of ideational and ideological diversity serves solely to protect vanity, and not to advance the human race or any specific cause, noble or otherwise.
Put another way, Complexity always best serves the cause of truth.
I am speaking formally, of course. From within the fold of ideas ALL OF US think some are stupid and some intelligent. We cannot do otherwise. But looked at in the abstract even apparently stupid ideas, even the ideas of people with missing teeth who live in broken down trailers CAN have value, if only in stimulating latent perceptions in the rest of us, in recalling to us, or summoning to our awareness, notions which otherwise would have gone missing.
You can never know what possible idea is missing from your current inventory. This is an absolute principle, and applies particularly to–is most useful to–the most intelligent among us.