Sure, I get that, totally. When you are in the Markdown view. But when you need to view the rendered rich text form, isn't it much more efficient and far more user-friendly to show just that, and allow it to be edited?
In other words, Inkdrop's two views could be Markdown and WYSIWYG (both editable), rather than Markdown and Side-by-side.
(Typora is nice, and popular, but it has some serious performance and usability issues. Some competition would be good.)