I am a fan of both Clinton Anderson and Pat Parelli, but it was Parelli's techniques that I used when working through ground issues with my pony. I achieved amazing results using his methods.
I think the reason Parelli gets a bad reputation for creating spoiled, rude horses is because Parelli is often picked up by inexperienced and uneducated horse owners. He puts his program in such a nice little package- "buy this kit, watch dvds, play the seven games, move up distinct levels, and then your horse is perfect!" I'm not saying this is what Parelli actually SAYS, but I think it's what a lot of the audience hears, or wishes they heard. So you have people with horses who are way too much for them, trying to play little games with them, claiming they are practicing "natural horsemanship," and it just doesn't work.