Probably--the mix of granular privacy with built in reading is good (although explaining granular privacy isn't easy for a marketer), and there're a bunch of other features that, if fixed, could be great.

But I don't think they created Vox to deal with LJ; I'm fairly sure, from the way it was marketed, that they just didn't know they were re-inventing the wheel, they appear to have bought LJ for the staff then realised they couldn't get away with that (then Brad left anyway).