SGML was an especially attractive choice since it is the standard of the Linux document project. However, the DTDs I looked at did not have the control that LaTeX offers. TeX and LaTeX were created with the goal of allowing beautiful books and reports to be printed and distributed. Many people feel that the informational content of a document should be the only consideration when judging the quality of a document. Documents are made to be read by human beings.
People are a strange mix of logic and emotion.
Like it or not, the physical appearance of a document affects the reader. A piece of writing does not exist in a void. Writing is made to be read. Thus, I've chosen a powerful set tools that allow the greatest freedom of expression. The Linux Nihongo document grew out of the notes I made for myself when configuring my Linux system with the JE distribution in 1994.