Ahhh...OK, I thought GP meant that posts don't succeed based on quality alone. That said, I do agree with Karma score not being the sole determiner of worth...however, all other signals have their own flaws (such as domain-based or keyword-based penalties) while being less transparent to boot.
Agreed! But it doesn't work like that. Those with bigger karma scores get a bigger boost for their posts. Their upvotes also count more.