If we agree that removing spam filters means spammers will use the least damaging spam vector to store data, I agree that removing all spam filtering is the right approach.

What if an attacker deliberately uses the most damaging spam vector? How would we counter this attack?

All discussions I hear assume spammers use the least damaging vector for #bitcoin.

I think this is illogical if a state-sponsored spam attack aims to damage bitcoin with unlimited funds.