I agree with mr ploppy that they really aren't mutually exclusive. But for a clearer response than the poll can indicate:
- Yes, I know how to create ebooks. (In code view.)
- No, I do not look at the code unless the presentation on my reader indicates that there is something wrong with the code.
- I fix the code if I can clearly see that it's broken or just wrong before even looking at it.
So my knowledge of the "guts" of an ebook does not cause me to care about the code unless, as I said, I can clearly see it does not display properly. It has to cause a readability issue before I'll even bother glancing at the code. And if I only need to shrink the margins, I'll just do a calibre quickie. I don't care if it makes the code "worse" - I just care that I can read the book.