Optical media was not designed to support partitioning.
CD-Rs and later derivations normally use the ISO-9660 file-system directly, without partitions.
DVDs generally use the ISO-9660 file-system and can also work with UDF file-system. The problem remains: No partitions.
Some Mac disks are written with HFS or HFS+ partition table instead of or in addition to ISO-9660. Such disks use the Apple Partition Map (APM) partition table.
Some Linux distributions' installer disks use ISO-9660 that coexists with a partition table, but the intent here is different: to support different media in different ways. When the image is burned to a CD-R or DVD, it appears to be a partition-less ISO-9660 disk; but when it's written to a USB flash drive, it appears to be a partitioned hard disk.
As a conclusion: a file system can definitely be designed to be able to partition ODs, but that would server a very limited purpose and that's why it was not actually done.