As I see it (as an engineer - not a writer, grammarian, or publisher), the main reasons for "some" of these failings are;
- Limited fonts available
- Mostly fully justified rather than left justified
- Limited viewing space (exacerbated by reflowing text at different sizes).
Advances in software & CPU capacity can address the first. The three taken together are, I believe, the main things that make ebooks have a "not perfect" appearance. {Please note that pbooks also have a "not perfect" appearance even though they do not necessarily suffer from these disadvantages.}
In addition, I tend to prefer the straight quotes.
