On your somewhat off-topic meta-comment about my lack of due diligence: lucky for me I don't need to break out Coq to validate an RFC draft to post a comment on HN, which despite my mushy-gushy feelings has resulted in a productive, curious, and educational discussion, at least for me!
On the point of stolen resources, true, the attacker doesn't care, but I think if we get to the level of resource symmetry in a protocol we've effectively throttled a class of attacks. There are only so many grannies whom a given attacker can pwn. Symmetry is relevant because it makes it that much harder and that much more demanding of your botnet. Besides, like you mention at the end of your comment demanding some kind of additional Byzantine DOS-tolerance is likely too hard of an ask.
> There are only so many grannies whom a given attacker can pwn
And at how many millions does that number start to taper down? Plus, zombie devices of all sorts are being used of course, so while there certainly does feel like some sort of resource-symmetry scheme would be, if nothing else, a satisfying solution, its hard to see logically how that would really help all that much for these sort of attacks.
On the point of stolen resources, true, the attacker doesn't care, but I think if we get to the level of resource symmetry in a protocol we've effectively throttled a class of attacks. There are only so many grannies whom a given attacker can pwn. Symmetry is relevant because it makes it that much harder and that much more demanding of your botnet. Besides, like you mention at the end of your comment demanding some kind of additional Byzantine DOS-tolerance is likely too hard of an ask.