So your solution is a cartel of miners decide to start dropping valid blocks? Why not drop all valid blocks and double their profits? They are already breaking the spirit of Bitcoin why half ass it.
They may decide that they don't wish to have their mining power used to support a massive fraud or theft. Deciding to drop valid blocks for that reason has a far greater ethical imperative than doing so to enhance one's own profits.
Theft for the greater good? Decentralized is too scary, bad people might do bad stuff so we should instead facilitate absolute control by a cartel who is almost certainly to end up doing bad stuff.
So your solution is for a group of miners to "solve" a potential theft by stealing bitcoins from other miners?
To avoid miners wasting effort on blocks, this could be phased in at a certain block number. There would be no need for miners who are following the consensus to surrender any earned rewards. It is just a matter of whether the majority of miners would choose to support what is just, that is all, and choosing not to have their own effort mining used to support a massive fraud or theft.
Consensus obviously doesn't mean what you think it means. 51% is not a consensus, it is a majority. Deciding who has the money based on majority rule is a terrible idea. The point is you have no possibility of a consensus so instead you would force your will upon the minority (potentially a very large minority) by extorting their valid mining reward to compel them to act against their own better judgement.