Interesting stuff.
Just... are SD capture cards unavailable nowadays, you don't accept SD submissions or people don't want to make SD submissions?
If either of the latter ones, i'd say that's a people's problem, ie lazyness or too high standards. This doesn't seem to be the case though, if i'm reading your explanation right.
I still maintain it is not an end to speedrunning scene... just the community due to too high entry barrier due to lack of theater or other in-game tools. There are always going to be people who insist breaking and setting records, don't think lack of those is going to stop them.
And this reminded me of High Impact Halo... or something like that. Trickster community. I assume it and HSH are somehow related? Anyway, lack of the same tools means trick videos are going to be rare, no? Something i'm far more interested in than in speedrunning (usually watching a vid longer than 60 seconds strains my patiency, unless it is fun or really interesting (fails or tricks when it comes to Halo)).
Still not sure how i should react to lack of theater and scoring. Something in me says i should complain about lack of them and emphatize with people affected by lack of them, otherwise i just can't bring myself to care at all since i rarely if ever used either feature.