There is no good reason to let putting shit on the blockchain. Filter spam is the answer. Its money not a database

But this isn’t a consensus level change, only for the mempool. We have seen that “spammers” are submitting valid transactions directly to miners and the transactions are getting mined. No mempool change is going to stop that. I’m going to avoid the philosophical arguments about applying the Spam label to some transactions. I haven’t fully thought out where I land on that.