This is in line with previous court rulings. The Naruto dispute <https://en.wikipedia.org/wiki/Monkey_selfie_copyright_dispute> is an example of such a ruling. In the United States, at least, an animal can't own a copyright and so the ruling was that the photographer whose equipment Naruto used couldn't own the copyright, and neither could the opportunists at PETA. So a ruling that an AI can't own one isn't so different. I can see some arguments either way for it, but right now this is the ruling.
I'll note that IP cases can be really complex and in some cases
don't seem so logical. The IP lawyers are to blame for this by
their activities influencing legislation and engaging in all sorts
of legal maneuvers in court cases.