Agreed, some Arabians are way too hot. They are also extremely clever so if you don't give them something to occupy those nimble little minds, they'll find their own amusement :P
I think in the States now they are classified as a breed, aren't they (Vanners)? I know a lot of English people were falling over themselves laughing re how much Americans were willing to pay for their patchy cobs, but hey, seems like they are gaining popularity. I think the sourgrapes are coming from breeders who are cheesed off those big spenders didn't come to THEIR farm. I think pretty much any horse is going to go mental without enough exercise, poor things, drafty/cobby bred or not.