'Music' cant really be judged since theres nothing to refer to. Only technique can be judged since a mistake, is a mistake 
That's not totally true. Any person with artistic leanings has to make a series of interpretative choices in any piece he plays. Those with trained ears, and years of experience teaching or playing, can most definitely judge a competitor by the integrity, coherence, and consistency of his ideas. Or they can judge them by how well those ideas reflect the written score.
I just noticed the wink at the end of your post. Maybe you were being facetious. In any case, if you join a competition, you accept to be judged by whatever standards they choose to apply. That is the main reason why they should be discouraged and avoided. You are in effect subjecting yourself to the whims of a group of disparate individuals, each fighting either for their legacies or for their protection in the industry, who have to listen to hours upon hours of pianists, and somehow are mentally fresh to adequately judge each one?
In Tolstoy's "Resurrection," a woman is sent to hard labor in Siberia, because the judge fails to instruct the jury that they can find her guilty of a murder without intent (she was tricked into poisoning a man). He was too distracted to get to the home of his illicit lover before a certain hour, that he forgot to mention the part that would save her.
Similarly, when we place ourselves in any situation to be judged, we take the risk of being subjected to pure whimsy. I don't think anybody should complain about it; either accept the fact that you can be excluded for non-musical reasons, or don't accept that a panel of judges can adequately judge you (in other words don't join the competition).
Walter Ramsey