I think a blanket statement like this is unhelpful. There are absolutely times when turning a horse out would be unacceptable: immediately after some surgeries, rehabbing specific injuries, etc. I recognize that’s different from a show, but a black-and-white declaration like that is a bit extreme.
To the point, I think turnout at the east coast shows isn’t utilized less because of the cost and more because of the type of turnout. A lot of shows use round pen panels for convenience, and the paddocks are small with square corners. Couple that with lots of new horses around them and an exciting and unpredictable atmosphere, and it can be a recipe for injury or worse. There are some venues with wood fencing and a little more room, and I see those paddocks sell out. Otherwise, we all spend a lot of time hand walking and grazing our horses to get them out of their stalls.
I don’t think anyone is or would argue that living in a box 100% of the time whether at home or at shows is in a horse’s best interests. All I’m saying is that there are multiple ways to meet their needs. I also want to be clear that I think turnout is critical—making sure our horses got outside more was one of the big reasons why we bought our place instead of remaining in various show barns—but I also don’t think any single day without turnout—be it for a show, injury, illness, or even dangerous weather—is inherently unacceptable.