That's kind of not true though - I had to train my boy in a halter because I could find a headstall big enough to fit his head. He was so responsive it was amazing. I don't think that would be the case for all horses, so that's why I say it's partially not true!
Yeah I can ride Soda just fine in a halter, but it's frustrating for HIM to try and learn the tiny distinctions that distinguish a well-trained horse from a plod in it. A halter doesn't allow you to explain the minute directions in specific maneuvers. I can teach him something much quicker with a bit that allows him to understand my smallest nuance than a halter that allows very little room for the subtle signal. I know he appreciates it as he's not a terribly paitent boy.
As for that whole bond thing. Soda seeks me out every single day whenever I'm in the paddock or pasture. This is a horse that sees me letting the dogs out of the kennel and will sit and whinny for me to come hang out with him. He whickers every morning and evening when I feed. In the afternoon when I'm working on barn projects in the paddock or just relaxing reading a book (yes, I'm pathetic I sit in my paddock and read books) he comes and stands by me and lips my books. He'll sit with me for hours. Don't tell me that I need a better bond with my horse because I don't train/ride him exclusively in a halter.
That would be nice. I've got a couple of friends that ride their horses bitless (3 bosals and 2 Dr. Cooks). The horses love it and are really well trained. I don't see why they should be excluded from a competion because of a horse' preference. Both of these ladies have other horse that are not ridden bitless, but they've gone with what each horse is most comfortable with.