The sensible solution for OP_return Spam

Would be to change the consensus and make it harder to add spam to the blockchain. Since running Knots will not change anything.

But since this change would have to be a hardfork it is a mortal sin in BTC land nobody is talking about it. And Core does not care, they are simply just there to not let BTC become p2p cash.

Try to bring that up in r/bitcoin, I dare you.