Why should i let ember load default stuff

I would like to understand why should i let Ember load stuffs if i'm not going to populate them.

One example..

When i access the url /posts, the route will load the template posts.. so, this will happen behind the scene:

export default Ember.Route.extend({
  renderTemplate() {
    this.render('posts');
  }
});

But.. if i use:

export default Ember.Route.extend({});

Will work as it should.. but.. WHY shouldn't why type? I understand the convention over configuration concept, but i like too type thinks like that.. you know? I don't like this feeling of.. "there is several things happening that i don't have fuc* idea.."

Thanks.