I disagree.
It can easily be used as an output plugin so that people with devices that do understand soft hyphens have access to them, it could be used for as part of the kindle gen output process if someone so desired. It is just a plugin. No one forces you to use it.
FWIW - JSWolf, you are fighting a losing battle for "what works or doesn't" in your particular e-reader of choice. The draft for epub 3.1 is out and they are moving to allow pure html5 as used in a browser to have equal footing to to xhtml for epub3.1 publications.
This allows future readers to simply use open web technologies based on browser engines (Gecko, Webkit, Blink, etc). So if soft hyphens work in most browsers now, they will most likely work for most newer e-readers coming down the rode.
I think the IDPF has finally realized, they are fighting a losing battle with epub 3.0 with its need for xhtml and proprietary elements like epub:switch, epub:type and epub:trigger and the like. The IDPF seems to be jumping ship for the open web standards with aria roles replacing epub:type, and the removal of all proprietary xhtml elements, and proposing to accept full html5 alongside xhtml.
If you are interested see the Editor's draft for epub 3.1 here:
http://idpf.org/news/first-editors-d...ble-for-review
Frankly, I think the days of the standalone e-reader are numbered anyway. Everyone is moving to tablet like devices with web-baser browser stacks.
KevinH