Thomas, apparently there are a large number of people who are crazy and/or smoking crack. Seriously though, I share your enthusiasm for the Exodus - my comments and those of the reviewer and others are not a complaint about the excellent pack design, but rather a request for an additional feature/capability that would great enhance its use range and comfort.
I and other potential customers are not asking for a permanent stay, but rather a removable stay - the weight penalty for a few loops to hold a removable stay and two pad loops against the back is negligible (the pad loops are an option that MLD does). Also see feedback from the many users of the Gossamer Gear Gorilla - I have never heard a Gorilla user complain about having the option of a removable curved 3.4 oz stay, and have only heard raves about the comfort and load carrying it adds. Having tried it recently, I fully agree - though I'd prefer volume closer to that of the Exodus as long as there's good compression.
In addition, the more supportive Ark hip belt is offered as an option on the Exodus for a reason. A well-designed stay and hip belt helps take weight off the shoulders - important for anyone carrying a heavier load or needing to protect/rest their back. Your back takes a lot of stress backpacking or running - anything you can do to share the load is going to be helpful over the long run. Your back might be able to take it now, but this may come at the expense of later...I know one local highly experienced very fit lightweight backpacker who recently sold his Ark after many months trying to make it work only because of the lack of a stay.
I have asked experienced users of this pack for the max comfortable load capability and the answer has always come back max 20lbs. There are plenty of situations where you will start a trip with more than 20lbs, or remain at above 20 lbs especially if you are carrying supplies for others. A removable stay will help quite a bit in those situations.
Ron and MLD, hope you guys are listening. I and quite a few other people I know would snap this pack up with a curved removable stay and pad loops.