Two reasons. First, although we are very concerned about the endangered state of the script, the sad fact is that it is hardly used anymore. Except for priests, the vast majority of Balinese use Latin script almost all of the time. Newspapers, books, magazines, etc. are all written in Latin script. Government signs, however, are required to be written in Balinese script (for historical cultural reasons) and Latin script (so that the average Balinese can easily read the signs). When people take notes, write letters, etc. they use Latin script. You can still find Balinese script on old lontar leaves which captures so much culture and history of Bali -- and Balinese school children are required to learn the script so that they don't lose their traditions -- but as a practical matter, it just isn't used anymore. Very sad, because the script is as beautiful as it is interesting (for example, there are characters that signify that the word is holy, characters to signify a glottal stop, etc.). We offer a chapter on the script because it is part of the Balinese heritage and culture that should be learned to get a fuller understanding of the language and the people, but not because you need it to communicate, even in writing.
The second reason we wanted to include instruction on Balinese script is that although the materials are geared primarily to those wanting to learn to speak Balinese, Transparent Language, whose software we are using, has a fabulous facility to teach nonWestern scripts in a captivating, fun, effective way. We thought that Balinese school children -- who are required to learn the script at school as a cultural matter since nowadays, few learn it at home -- could benefit from this program, so we also included it as a resource for them.