I think the biggest issue with ED is that everything is the same.
I travel to an anarchy system and go to a pirates unsanctioned outpost and it looks exactly the same as the industrial outpost you visited in the high tech system a few minutes ago, aside from the fact that it has a red skull hologram on it of course. A pirate outpost should look beaten up, like it's been put together from bits of old ships. The lights should flicker. It also shouldn't be out in the open orbiting a planet with a big red sign that's basically saying "HERE BE PIRATES!". It should be hidden away in an asteroid field or a nebula and only discovered by picking up a bulletin board mission that takes you there, or by exploring. Also they should be more frosty towards strange ships entering their space.
Dictatorship systems should have a much bigger military presence. They should be distrustful of strangers. Their stations should look more military too. Rich systems should have huge and impressive stations. Tourist systems should have stations with observation domes on them for sight seers. Poor systems should have smaller stations that look a bit beaten up.
The Empire, Federation, Aliiance, etc should have different architectural styles. If we look at Star Trek as an example, it's pretty easy to tell the difference between a Klingon, Romulan and Federation ship or station. Even here on earth you can see that things designed in Russia or China have a different style to things designed in the US or Europe. Buildings are different, clothes are different... Everything in ED is cut and paste.
Years ago I used to play World of Warcraft. The main thing that stuck out in WoW compared to ED was the diversity of design. Each of the different races had their own architectural style. You could easily tell the difference between the Dwarf, Orc, Night Elf and Blood Elf, etc, capitals. Also the journey to reach some of these capitals could often be a long one fraught with danger. I can remember playing as a Night Elf and having to travel to the Dwarf capital for the first time past crocodile infested wet lands and mountain passes full of bandits. When I finally got there, after dying a few times en-route, the sight of the place with it's giant forges and molten metal spewing from the ceiling into giant pools was amazing. I had a sense that I was on an adventure in a living, breathing world.
This is what I don't get with ED. I feel like I'm flying a ship in the Milky Way Galaxy, but I don't feel that I'm really on an adventure because everywhere is the same. The same types of missions, the same station designs, the same ships. When I'm in a war zone, I want to find missions that are to do with the war. Maybe I could get involved if I'm feeling heroic and help the locals fight off an invasion. If I'm in an area full of pirates, I want to be able to work with or against them. I want to meet an NPC who's lost something valuable and I voluteer to find it for them, going on a journey of discovery through multiple systems until I reach my goal.
Basically I want it to be like all of the space and science fiction stories I read as a kid, and I still read as an adult, with space pilots that go on amazing adventures. I want to travel to a system and find a colony built into an asteroid. I want to meet bounty hunters and crime lords. I want to infiltrate an enemy base to steal plans or rescue a princess. I want to encounter smugglers. I want to get caught up in an intergalactic conspiracy. I want to discover alien races. I want to get caught in a plasma storm and have to find my way out.
Admittedly much of what I've said above may be completely beyond the scope of the game or what the developers are capable of (no offence), but at the very least the ED galaxy should have some character to it beyond 10 still images of some meaningless political nobodies, some news stories and 3D Risk in space style gameplay.