Edit: A DDoS against the Monero blockchain would the require the attacker to keep paying fees in order to maintain the blocksize at a given level.
I largely agree with your comments - the blocksize debate is not just limited to a simple technicality, it's a question for how Bitcoin can grow without pushing out many users/use cases that can't fit in under a high fee market.
To the point quoted above, how does this work when the attacker is also a large Monero miner. The fees they'd be paying would largely go to themselves, no?