The middle class guilds sitting at 11/13H right now like mine wipe because all the bads we've been carrying can't do independent responsibility fights like Heroic Lei Shen. We never had DPS issues in any Heroic ToT fights, to the point where they were all carried by the frost mages. :P
Don't worry though, we frosties feel the guilt. I know I could be carrying the baddies even more effectively if I was fire. But then I'd be miserable and stop raiding all together, so there you have it. You're not wrong with your points or anything, just that... skilled players can do these fights even as frost and DPS isn't the issue except right out of the gates (ilvls come easy and make up for spec differences), and right out of the gates isn't where most guilds progress. You're at the top so it matters a lot more for your guild.