Functionality is not everything and besides it’s not a stopwatch; the second hand never stops so what difference would it make? I see it as a solid visual base on which those Roman numerals sit.
Perhaps we could ask what aesthetic value all those little white lines add to that busy dial?

Compared to the lack of little lines in this placid dial …


Put on an Oriental (eastern) mode of thought 💭 vs a Western analytic one, and see if you find another way the phrase the question about the lines.
If that doesn’t work for you, I think you will be unhappy with Seiko, for much of what they do is inscrutable. At least that’s my take on it after 15 years of trying to unravel the “why”.
🧐
Cazalea
Or did they just have a batch of unused chapter rings wanting to be used up? Who knows?