Yes, and what I'm saying is there is no cartel. A cartel implies there is some barrier to entry (for example by limited capacity of equipment). There is none here; everyone can mine, and in a protocol that hasn't reached the stage of specialized hardware, the startup costs are low and entry is very rapid. A huge amount of mining would come online within a day or two, and remember your proposal is for all this to be announced a month ahead, so plenty of time to get ready.
You are making a valiant effort smooth, but it is not one you are going to win with this one. He make the same argument with me, in that a mining cartel could "block" all transactions they want. He refused to acknowledge that a non-conforming cartel would simply be removed from the pool, and the network would continue with the remain honest miners. He refuses to understand that the network will continue as long as there are some remaining honest miners to generate blocks.
I refuse to believe that he can not understand this, and instead believe he is simply trying out and testing new FUD against bitcoin here. Some FUD is easily refuted, other FUD requires more discussion and understanding. He has already said that he is working with his government on educating the public on the scam that is bitcoin.
I also get the impression that we are writing a paper for him, that discredits his imagined dystopia.
Sure it could happen, it would just take a massive preponderance of stupidity and/or lack of self interest, or coercion.
If it did happen, I would suspect the coercion first. Most miners of any significance have plenty of self interest and very little stupidity.