This is the first I heard about horses leaving but I have posted on several boards including Australian one.
Running martingales, boots, polo and unbraided manes seem to be the norm for the lower level schooling shows.
There even one post with pictures of the dirtest horse in the ring I have ever seen and when I question it I was told that it was no big deal and that it was only a schooling show.
When I read posts from people from that country that show they care about what they look like and that the level does not make a difference in attitude....then and only then will I change my opinion.
I posted photo's of me riding in the state champs earlier this year, I can assure you, I scrubbed that horse until every trace of dirt was gone, plaited, rugged her up head to toe and kept all my gear in perfect condition, shining and clean to look the best I possibly could. This also seemed to be the way for every other horse and rider I saw out there.
Don't judge until you have had to experience and seen something first hand, you clearly are very ill-informed.