I've been thinking about this some more and realized what was really bothering me about adding the author bio as a module setting in the blog. It makes sense in the html content feature because it is just one article, but what is bothering me about the blog is that we have more and more settings at the module instance level that really should be at the post level so they can be set per post. I've had to do item for a long time for example to make the map settings per post, so any given post can have the map configured any way that makes sense for the post itself instead of having to make them all use the same settings in every post.
So my plan now is to try to get to these things that really should be configurable per post. I will probably also add a module setting for "Show Author Bio" but it will really be just a default so that the corresponding checkbox for Show Author Bio in the post edit page would be pre-checked on new posts if true in the module setting but it could be unchecked on any given post. I'm going to review each of the blog module settings and consider whether to remove them after making the post level settings or whether it makes sense to keep them for default purposes.