I don't think the 'important to the userbase' thing matters so much. Vox was launched because 6A thought there was a gap in the market that it could plug. It was supposed to be a simple to use platform that allowed privacy and inbuilt reading, etc.

I think there is a gap in the market for that, or at least there could be, but that LJ, with a complete usability makeover, could've plugged that gap, whereas Vox simply didn't.