Somebody's mad that the bads his guild has to carry to fulfill the epeen requirement is holding back progression. Having said that, I agree that 16's are more fun and have always been my guild's goal. Are they harder beyond getting the right personnel...no. You could make the argument that 8-Man's are harder because one mistake usually ends in a wipe while the bads you are carrying around are face first on the ground but the scaling from 8 to 16 accommodates that.
Btw, what Serious Progression has your Serious Progression based guild accomplished? Got past the medpac phase on T&Z yet? I kno that mechanic is much harder on 16 man.
Sure you can make the argument that 8-man's are more difficult. I can also make the arguement that Jacob is better than Edward Cullen and that my ancestors rode on raptors. Guild progression statistics may disagree with your assessment as no 16-man guild has been able to complete EC Nightmare. But who the hell cares about "facts", damage multipliers based on raid makeup or statistics. Those are just words meant to confuse how you feel in your gutt...
As for my guild I can only say that we have yet to beat 16 man EC nightmare. It's the most challenging and frustrating ops we have ever had the privelege of running. Mad props to the first 16 man that completes EC Nightmare. Cause you deserve it.