Video Bloggers... ?

I have a quick question..


Why are so many book bloggers readers of YA/NA books only?


How come I so rarely see anyone that v/blogs adult novels, scifi, fiction, history? Where are all the readers that aren't obsessing over teen books?


I don't mind YA/NA once in awhile but it would be nice to see more people v/blogging about books geared for everyone else.