Glad you mentioned Mayorga - he's the perfect example. Every weight above 147 he's glass-jawed. Just like Garcia will be. Hence the point of the thread and my mentioning of him in it.
You're mistaking a glass jaw for having no head movement or defense. If you take multiple punches to the face from a hard puncher and you have no defense, you're gonna get knocked out. Doesn't matter if you have a glass jaw or a titanium one. Jeez, some people dksab. atsch:rofl Can't believe this is even up for debate.. Mayorga having a glass jaw.. atsch:huh:-(
So, going by your reasoning, if Garcia was to be one-punch KOd by Guerrero in his next fight that would be because of bad defence, despite having no credentials at the weight, but if Khan was to be one-punch KOd in his next fight it would be a glass jaw? Effectively, by your reasoning, you can argue that nobody has a glassjaw then and that everything can be laid at the feet of poor defence. If not, who gets to decide if it's a glass jaw or poor defence? Mayorga at <154 - warrior, with a solid chin. Mayorga at 154+ - 11 fights, lost by stoppage 5 times. Does he need to lose all 11 before we can say his chin doesn't hold up at the higher weights?