You have failed to understand what consensus is when you refer to participants as rebels. ASIC tech and the "cartel" are at the mercy of the network participants not the other way around.
In essence making all existing ASIC use for BTC obsolete and make the old BTC network compromised and useless.
Sorry, I believe that you failed to understand.
All the ASIC and mining installations will remain perfectly usable with the 25 M chain, and would mine it because there would be no other chain that they can mine.Ater the "Red Button" solution there will be two fully functional versions of bitcoin, but one will have a 300 PH/s network, the other will have a puny CPU network. Even "hero miners" with older ASIC miners in the attic will be unable to come to the help of the second one.
BTC network used to fund accounts would be under suspicion of double spent coins due to the "cartel" having over 51% and closer to 100% network control. BTC network as it was known will have become defunct.
Whether the attack succeeds or not, the concentration of hashing power in the "Big Bitcoin" network will be the same as it was before the fork point. The change to the halving schedule will not affect the possibility of double-spend. In fact, that possibility already is not negligible now. (Imagine that some hacker steals 500 kBTC from the US or Chinese government, who is determined to get them back.)
The risk of double-spend will be much higher in the "Small Bitcoin" CPU-only network, since an external agent could gain majority mining power with a relatively small investment.
