I think this is reaching, by a lot - not every "feathers behind the back" is "warbonnet imagery" and artwork is subjective, so I have a strong feeling that your personal art headcanons on how it should be drawn are influencing the demands to change it. Here's a picture of a Crested Grebe that, if drawn in cartoon-y FR way, will likely invoke the same misplaced ire: https://www.wildlifetrusts.org/wildlife-explorer/birds/grebes-and-divers/great-crested-grebe