I tend to agree with this, and haven't posted mine for this reason. I've spent an embarrassingly large amount of time going through everyone's reported GPA/GRE scores on the results page, and the only consistency I find is that none of it is consistent. You'll have an accept and a reject from the same school with average and super high scores, respectively. While some schools might emphasize those scores above all else, we're not getting any kind of clear picture without also knowing the posters' fit, LOR quality, SOP quality, publications, etc.
A candidate with a perfect scores could see that a poster with lower scores got accepted to their top choice school, and be given false hope, not knowing that they're about to get rejected for something unrelated to those scores. Or worse, they could assume that there's some sort of injustice happening, when the fact is that they weren't a good fit, despite having good test scores or a good GPA.
While posted scores are something fun to look at, I don't think they provide any good intel into a program or a candidates' likelihood of admission.