I’m not sure I entirely agree. I’ve seen pictures of ruins in Chechnya that I found very intriguing. But I think the biggest reason is that ancient ruins are exotic, they don’t look like the buildings that surround us every day. Meanwhile, depictions of future ancient ruins are highly stylized, they’re designed by the creators of the images to be intriguing. They’re not entirely accurate, but rather ruined and highlighted in specific ways to increase visual interest. There’s also the emptiness factor. Modern ruins are used, rebuilt, re-purposed, squatted in, and vandalized. Ancient ruins are usually protected, and if not they are over-run with jungle. Future ancient ruins are usually largely abandoned, or are populated by life-forms quite different from us, or at least humans who live in ways we do not.