First. Your problem is considering spam the data that you don't like. Second. Spam filters vs Spam is an arm race where pro-filter need to update their filter algorithm. This inevitability relies on trust in a authority. Third. Bitcoin Core decision incentives spammers to use OP_RETURN for Ordinals instead of Witness data that can increase UTXO set. View quoted note →

The question isn’t whether the heuristic is simple or complex. It’s who decides what’s monetary vs non monetary data. OP_RETURN limits made sense when they were consensus rules everyone agreed to. Post Taproot, inscription data pays full freight in fees and follows consensus rules. The “arbitrary data burden” argument cuts both ways: if someone pays market rate for block space, that’s the fee market working. Configurable filters are fine for individual nodes, but marketing them as “spam protection”implies some uses are more legitimate than others. Bitcoin’s neutrality is its superpower. Once we encode “this data is worthy, that data isn’t” into standard policy, we’re making subjective calls about what belongs on a permissionless ledger.

No this isnt framed right. The decision of whats monetary or not is much sinpler and objective than how your portraying it. Bytes after Op_RETURN are non-monetary arbitrary data but a small amount (40 or 80) had been tolerable. Data put here for images or video is obviously spam and not directly part of any tx and is spam. Data in the inscription exploit by way of taproot is obviously spam. Same for data hidden in fake pubkeys etc. Spammers pay the price once paid to get in rhe blockchain and then node runners are forced to bear the burden forever into the future. For legitimate monetary transfers of Bitcoin thats ok, but not for shitcoins on Bitcoin, nor JPEGs, or any other other data other than a hash. BITCOIN IS NOT A NEUTRAL FILE STORAGE PLATFORM. That is a corruption of its purpose as money

“Obviously spam” is doing a lot of work in your argument. The moment you need humans to define what’s “legitimate”, you’ve introduced subjectivity. Consensus rules are objective. Everything else is opinion about how those rules should be used