Ruiz was not great. He was not even very good. How can you say otherwise. When he fought a real heavyweight in Tua, he was knocked out in seconds.
It's worse than that. Not only is Ruiz mediocre, he used illegal and shameful tactics like excessive holding and faking low blows - and his connections with powerful promoter Don King - to get undeserved decisions over fighters he could never have beaten WITHIN the rules. Ruiz is the poster boy for boxing corruption. A glorified clubfighter who would have been lucky to be a fringe contender without King's influence.