If there is a real rejoinder to this, I have yet to encounter it. This depressing observation is regularly voiced (or thought) every time UX aesthetics come up

If there is a real rejoinder to this, I have yet to encounter it. This depressing observation is regularly voiced (or thought) every time UX aesthetics come up... and I've yet to see so much as a sniffy defense. My assumption this is because it's simply true; the only reason for churn is "fashion" requiring orbiting around a small space of viable options, strange-attractor style, and the vested interest an industry has in fueling the very modest pleasure that comes from tiny or bold steps from what is familiar to what is "fresh."