This apparent oversight led me to briefly test the waters of BigBox. I had examined various videos of BigBox in action and determined that it did not suffer from the same issue, and indeed, BigBox uses hardware acceleration for videos by default.
Unfortunately, BigBox has major drawbacks that I didn't discover until I had it in front of me. Specifically, it is hardcoded to load visual assets in a certain timed sequence. The upside of this method is that you minimize the chances of disk access causing visible stuttering (which is definitely a problem with any AttractMode theme you'd care to name). The downside is that you have no choice but to wait on those assets to load if you want to see more than just the game logo. A video snap, for example, always waits exactly 1.0 seconds before loading. And as we all know, the video assets that have been widely distributed all spend their first second fading in from black. That is a long time to wait just to get an idea of what the game looks like in action, especially if you're specifically trying to skim through titles to find something interesting.
It's a big enough problem that I consider my purchase a complete waste, on top of other issues like the extremely long loading time, the unresponsiveness of the interface, and the fact that wheels can't be told to have a sub-100ms transition time. Basically I'm glad AttractMode exists, and just sincerely wish the dev would take those few minutes to flip a switch so the PC version can get videos playing with hardware decoding.