It doesn't matter how we feel about it, what matters is what the truth is. Is relay policy effective at preventing consensus valid transactions or is it not?

Take the spam debate out of it and just focus on that question itself.

It seems to me that the answer is it is effective if enough nodes do it, and you don't have a side channel with a miner.

That suggests to me that the social layer is an important determinant of censorship resistance, over and above what the consensus rules are. Broad censorship resistance can only be maintained if enough nodes agree not to censor.