The problem with making a world feel believable and lived-in is a hard thing to do with computer games. Frontier didn't have much choice with Elite Dangerous because it's set in the Milky Way galaxy, thanks to FEII being set here. If FEII had stayed set in 1984's Elite universe, that's where we'd be now with Elite Dangerous, a smaller game world (in this case, a galaxy). In some ways, Star Citizen are taking the right approach with focusing on a single system, and the oft-repeated phrase of "A mile wide and an inch deep" is not without merit when it comes to Elite Dangerous, because a galaxy of 400 Billion systems is hard to make feel populated due to its sheer size.
I don't have the answers, and I don't think anyone does, not even within Frontier. If someone had the answers and made a perfect Space Game, then we'd all be playing that. We all make compromises with the games we play, even hardcore simulators like Microsoft Flight Simulator, simply because it's not real, it's a simulation. Where people in the Elite community are finding dissatisfaction is, I think, because there are too many compromises being made by Frontier in the wrong areas for the player's enjoyment.