With the normal translation there is a filter that checks the languages of the node. So you could for example only display the nodes that are in the users language.
With Entity translation this filter doesn't work because the node is in 1 language en the field are translated. The problem now is that if a node is published but no translation is provide a message will be displayed that the node is not translated or it will show the node but only the fields that can't be translated.
By turning on 'Enable language fallback' the node will be displayed in another language but this is an overall setting and maybe you just want this for certain node types or views.
So a filter that can be set per view would be more flexible. Maybe something that checks if a translation for the node is added?