I have seen only ever seen 2 people actually post the heads that they had rejected here, and both of those cases were solved. To me it is strange that someone gets their head denied and thinks "damn admins don't know the rules!", and not "maybe there is something wrong with my head."
FYI staff do get trained on uploads... Uploads are an interpretive job though, some customs are absolute rubbish and not all staff will understand what is going on with it, so expecting the entire staff team to come to a unanimous decision on a graphic would be ridiculous.