There is volumes of science and engineering that has gone into this topic, but I am not here to teach. But I will be more exact with my point of view.
I find the statement "Forget acoustic ratios....its a nice to have, but you're still going to need to treat it." to be misleading. This implies you will have to treat the room anyway so its no big deal. But it is important and as Cathan warns "don't build a cube" this is due to the severe problems that it will cause which is the point I am making, and you can't treat those problems away.
So if you are building a room, and if sound quality is important to you, then room ratios is an important element of the total picture. This is in addition to the other elements of screen, seating and so forth.
Now for the other view, if you are setting up a casual home theater where audio is not that important to you then its it does not matter since many people don't care if the room reverberates at 80 hz or stereo imaging is non existent. most rooms would work well and get you lots of thrills no matter what ratio you have.
But here is the critical point that many might ignore, if you have spent some time with high end audio then pay attention to room ratio, you will notice the effect by a large margin. If not, then it wont really matter (but still don't build a cube)