@buffaloseven: It is no where near as simple as that. In the epub, all these settings, justification font, margins and line spacing, are set in the styles. Different styles have different values for each. The styles should then be used in different places to help the reader see what is going on.
As an example, for most of a novel, justification doesn't matter. But, a fairly common thing in a novel to have a newspaper article, a letter or something else. These are generally displayed to make them appear different. The ways this is done changes, but it is some combination of a little space above and below, wider margins on both sides, a different font or all capitals and justification settings. For a newspaper article and the transcript of a hand written letter, different justification settings would be used, fully justified and left justified respectively. Using these gives a bit more information to the reader
If the device overrides these sort of setting, then the reader loses information about the book. The device could override some of the styles, but which ones? And if it disables the options in the settings dialog because one style has the setting hard-coded, that means the reader can't adjust the other parts that it is safe to adjust.
Personally, I think Kobo are close to right on this. They allow the user to make changes but respect the books hard-coded that might be important to the book. What we need is for the book designers/creators to create ebooks in such a way that readers can change settings for anywhere that the formatting isn't important.
Last edited by davidfor; 02-02-2013 at 06:58 PM.