Miners should be able to easily detect erroneously high fees in the same way they detect transactions with too low a fee and also reject them outright. There is no philosophical argument required.
True, but due to the nature of the private sector this is unlikely to actually happen. As long as we use a currency which is trying to be decentralised and manages its transactions through rewards, many miners (especially the smaller ones) will continue to take these fees for themselves.
I don't even believe that Bitmain would have returned the fees if they didn't expect the miner to make the error public and potentially damage their image.