I'm referring more to the acting of choosing. I think for many it's easier to choose your display device and be happy with it for years (though, as you say, upgrades are far more frequent on the video side). For audio, the very act of deciding what you want is plagued with choices bordering on...
One aspect driving the "spend more on video than audio" consideration is that--at least in my opinion--it's easier to decide on video and consider your upgrading "done for a while." You also have relatively fewer choices for your video "solutions" than you do with audio.
If you are a projector...
Phew, I'm glad I held off on the NX-9. This is what I've been waiting for.
We're demolishing our house next year and building from the group up (literally). Unless reviews go sideways I'll be going with the DLA-NZ9.