We should not be arguing about this. Spammers say you can’t define “spam”. It’s not that difficult- if you need to attach large amounts of arbitrary data, or hide it in massive amounts of unspendable “dust” outputs, then it’s not a financial transaction, and belongs somewhere else that’s not on the bitcoin blockchain. I agree there’s a bit of a slippery slope here - like how side-chains anchor on the base layer blockchain, and we should periodically reconsider how much arbitrary data is needed for financially adjacent use-cases.