I agree using `unless .. else` without purpose is bad. I've used this here intentionally
```ruby
    default_message = unless request.xhr?
                        _('Invalid parameters sent. You may have mistyped the address. If you continue having trouble with this, please contact an Administrator.')
                      else
                        _('Invalid parameters sent in the request for this operation. Please contact a system administrator.')
                      end
```
because first branch of the condition is standard HTTP request and the second one is XHR which makes it for me special so it goes to the second place. Anyway I just wanted to explain why I sometimes use `unless .. else` and that there are situations where breaking similar rules deliberately is not a bad thing. But if you don't agree I'll change it.