I think there are quite a lot of surgeons who are "good" i.e. will produce a decent result, OK bite, not kill you or give you some infection. A lot of surgeons don't post before/afters so we don't know much about how good/not good they are.
Eg. in the UK there is Johnson, Sneddon, Thuau plus at least 5 decent NHS guys. But none of them put much online.
However, the surgery is so major, can have a huge impact on the face, so expensive, and such a tough+long recovery and is difficult to redo the most people want a lot better than "good" or "adequate" - the want "excellent". It's just not the kind of surgery you go through for an OK result
ALso, most of us here are the ones who are doing the most research, and are the most educated about the surgery and we want excellent results - therefore we are looking at only the top 10% of surgeons. A lot of people don't do this and take the surgeon suggested by their ortho