[yencabulator]

A separator separates two records, where as a terminator terminates a record.

You can detect and error out if you see an unterminated record at end of transmission. With separators, the producer might not put a separator after the last record, because there's nothing to separate it from there.

There's no justification for not using terminators, it's just a bad spec. Unsurprising story: the variant with better marketing has less technical chops.