Why EVA display of views is added to the manage display of content type?
From the EVA project page:


  "Eva" is short for "Entity Views Attachment;" it provides a Views display plugin that allows the output of a View to be attached to the content of any Drupal entity.


(...)


  The placement of the view in the entity's content can be reordered on the "Field Display" administration page for that entity, like other fields added using the Field UI module.


Apparently it did just what it claims it does.