@Riot: Why can we not toggle on a range indicator?

Rapidfire Cannon has given us a ranged auto-attack indicator for the first time in League's history, and it's amazing.

I was wondering if there's a design reason behind not allowing us to toggle a similar indicator to show our auto-attack range at all times.

It would add a lot of clarity to champions with changing range like Kayle, Tristana, Kog'Maw, Twitch, etc, and allow ranged characters to fully know the effective range of their damage, instead of just their abilities. I'm not sure it actually offers any real downside (if toggleable), unless knowledge of the edge of your range is considered to be a major power boost.

Thoughts?