Ive had about 30 goats now, bucks, does and wethers, and never had issues with any trying to butt people. We are very careful to never encourage that behavior in the little ones and none of the older bucks have seemed at all interested in doing so.
I purchased a registered mini-lamancha buckling in the spring and when I was spending time in his pen two days ago, he was very interested in rubbing his head and pushing against me. I smacked him, thinking that would dissuade him, but I think he just saw it as encouragement, so then began to rear up. I then reached down, grabbed, his off side legs and plopped him on his side and held him there for about ten seconds till he stopped struggling. He is a very, very sweet affectionate boy, and loves to be petted, so I think he is just playing, not being mean, but all the same it is absolutely unacceptable behavior, given he could hurt someone.
The above was my in the moment response, but I was curious as to the best way to teach a "butty" goat to stop attempting to play with people this way.