Low starch does not equal low fat. Feeds such as Copra are extremely high in fat and yet are low in starch, sugar and NSC's.
The fact is, horses are not designed to process large amounts of starch and sugar - Bad things happen when they are made to. Horses are designed to be constantly taking in forage - bad thigns happen when they can't.
It has always boggled my mind that the majority of horses in the US aren't on grass, ever. I have never met a single person who keeps a horse off grass here in AUS, and it is rare to find anyone who has their horse stalled any more than just nights. My own horses are on grass 24/7.
In the rural areas, we definitely like grass. Ice came from a 24/7 grass situation, and up in Ocala there are acres and acres of grass fields. Or there used to be...I haven't been up through there since the drought got really bad though. A lot of people here on HF in the Midwest have 24/7 grass situations.The US though is mostly suburban area, where grass spots bigger than your car are hard to come by.
However, I will agree that we like our barns. I have no idea why.