Last year the final round was judged in a single session, for beer anyway. There is already room there so long as that many good judges keep attending the conference.
If they go with a lottery system and I get shut out, this National judge will be staying home. I likely won't volunteer my time to judge at a first round judging site either. Don't piss off your judges and volunteers by excluding them or the whole thing will collapse quickly.
There are hundreds of competitions around the country for people that "just want quality feedback". NHC should not be one of those competitions because the demand to enter is to high.
I tend to agree with your bolded statement, though I'll still show up to NHC/Final Round judging if I'm not picked. Wait, unless threatening not to show up will get me on the list?

I think there are reasonably fair ways to give preferential treatment to winners/volunteers and give everyone else an equal chance. Lots of them have been mentioned here, and I think all have some merit.
lottery of 100% of spots will lead to different uproar, not less uproar than last year, IMO. Taking quality of the average competition beer into account I don't consider 100% lottery an improvement at all.
cheers--
--Michael