I don't understand. If anything I would guess that our (human) perception of "weirdness" is not a good measure of the (dis)advantages of a particular attribute.

I don't understand. If anything I would guess that our (human) perception of "weirdness" is not a good measure of the (dis)advantages of a particular attribute. Octopuses and angler fish are weird as hell (to me at least) but they fit their biological niche pretty well. (Of course we could say that any attribute has advantages and disadvantages but at that point the claim becomes vacuous.)