I used to know a fair number of mushers in my area. A couple made it to the Iditarod, one returned shortly after arrival and never entered the race, just came home with his dogs. The town had a couple fund raisers to help him fund the venture, it took him a few years to prepare.
After he came back, nobody said much about it. They guy was a local favorite and fun to encounter at the bar, or anywhere else, super intelligent and empathic. I finally got to ask him what happened a few months later, he lived up on the mountainside so running into him on town was not common.
He sat me down, bought me a drink and told me how inhumane the whole thing is for the dogs, said he couldn't treat his dogs like that, wouldn't do it, said fuck it and came home. Apparently there is an expectation that you will lose a given number of your dogs along the way for not so forgivable reasons.
He died a couple years later while out at his dog pens, he was out to put down one of his old and ill dogs, he didn't get that far, suffered a fatal heart attack and was found by his partner about an hour later when he didn't come back in. Everyone in town was devastated, he was one of our town favorites, he lived in a teepee at 7500ft and would give you the shirt off his back if you were in dire straights.
From him I learned that the race is an abomination to anything related to anything called sport with exception of blood-sport. Anyone who has respect for their dogs would eschew this event out of repulsion.