As if it's to prevent the species from over-indexing on a particular set of behaviors.

Like how divisive films such as "Signs", "Cloud Atlas", and even "The Last Jedi" are loved by some and utterly reviled by others.

While that's kind of a silly case, maybe it's not just some random statistical fluke, but actually a function of the species at a population level to keep us from over-indexing and suboptimizing in some local minima or exploring some dangerous slope, etc.