You can refer to this issue Angular: Why doesn't CSS justification work with ng-repeat?
This issue use ng-repeat-start and ng-repeat-end to fix this:
<span ng-repeat-start="tag in tags"><a href="#">{{tag.name}}</a></span>
<span ng-repeat-end></span>
The reason why you have this issue is because of the HTML ngRepeat created lacks the correct spacing, and the justify css property will not work correctly. So what you need to do is add the correct spacing.
Also, if you use directive to add some extra elements, and you want it to work with 'justify'. You can use '\n' to create the spacing like this:
element.append('<span><a href="#">Extra element</a></span>\n');