Why?

As they become more popular and more frequently used to rate horses, it stands to reason that the top rated horses will be more heavily supported = shorter odds. Most punters will use similar filters so the top rated horses will be consistent. I expect that these top rated horses will have an impressive strike rate, but will they have the odds to support punters consistently winning. The answer is no. The punter will conclude that maybe they just haven't got the filters quite right and will continue to tinker because he /she is ever so close to the HG (Holy Grail for the unwashed).

I've only ever been wrong once in my life and that was when I thought I was wrong!