Synchronized text+audio is very important for accessibility of digital publications, as seen by the popularity of DAISY standards and now EPUB+MO in the print-disabled community.
The argument, "support across rendering engines is in very bad shape", can be made for many other features (including non-EPUB-specific Web technologies). But there are some RS which do support EPUB+MO fairly well, and there is definitely a legitimate use case.
I believe we can't just drop this use case without providing an alternative solution.
I disagree with the following conclusion:
Synchronized text+audio is very important for accessibility of digital publications, as seen by the popularity of DAISY standards and now EPUB+MO in the print-disabled community.
The argument, "support across rendering engines is in very bad shape", can be made for many other features (including non-EPUB-specific Web technologies). But there are some RS which do support EPUB+MO fairly well, and there is definitely a legitimate use case.
I believe we can't just drop this use case without providing an alternative solution.