It was legitimately defensive holding. The announcers on the replay verified it, showed it. It was clear. What exactly is ticky-tack about that? If an illegal hold impedes a player from possibly making a play... and he gets caught, the flag and penalized yardage are warranted. It was the right call. I don't get where you're going with this. I don't think the emphasis is intended to hurt the Hawks. Some (those who don't like the Hawks) try to go there. But, there was some analyst just speaking to that yesterday in one of the many pre-game hype shows and speaking to how the Seahawks teach DB skills. It may have been Eric Davis who was coached by Pete Carroll at one point. He was giving Carroll's attention to detail props.
Michael Irvin and Steve Mariucci did a piece on NFL gameday showing the difference between defensive holding and illegal contact. There example was overly blatant to be clear to the audience. But, if you grab, hold, etc. - it's holding. Rules is rules. I think players must work to be crafty about disguising and getting away with enough to give them an advantage. But, that particular incident was not well enough disguised to not get caught. It was a stupid play by the defender, too. Didn't he or one of his teammates point to his helmet after the enforcement as if to say, "Think!" ? That was just not a smart play by him. Wasn't it the LB, Jones?
Hope that helps.