As the OP mentioned, a huge number of people playing ED will never realize there are any problems.
It's only when you try to play with the same people over and over that it becomes evident. Running through space randomly meeting people, you'll never notice that you can't talk to somebody or you're not seeing the same thing in an instance. But when you try to play with the same wingmates and get "Unable to connect" message you know you're in trouble. It was stated by FD in the dev thread that dedicated co-op missions weren't going to be implemented anytime in the near future. That makes no sense with the addition of wings. On the one hand, they want you to team up. On the other hand, they don't seem to want to provide any in-game incentive to do it. It's pure speculation on my part, but I'm starting to think that it's because they tried it in-house and couldn't make it work reliably. If they released it to the general public in the current state of the game, all it would do would generate complaints from players who see completely different things when in the same instance, let alone trying to sync up mission objectives and payouts.
I really, really hoped CQC was going to force Frontier to acknowledge the shortcomings of their network models. With CQC they are effectively forcing players into the same instance. But look at what they've done... Max 8 ships instead of 32. They've simplified the flight model. All weapons are auto-aim. It's like they knew that their P2P scheme wasn't going to be able to handle it, so they scaled the game back in a big way to keep things from getting out of control.
And if you go look at the CQC forum, it's still a mess. People are unable to see other players. Warping. Lag. Inconsistent performance. Unreliable matchmaking. Some people can't even see anybody in their games. As part of the 1.4 installation instructions, it's mentioned that UPNP must be enabled, but a lot of ISP's don't even support UPNP, or deliberately block it because they think it's a security vulnerability. Yet it's now a requirement? Sure, there's a manual workaround, editing an appconfig file, enabling port forwarding, and opening a port in your firewall... But honestly, how many other games in 2015 need this kind of extra effort to play multiplayer when it's an advertised feature of the game.
And there's the rub. The game requirements make no mention of minimum bandwidth requirements or quality of service. They make no mention of UPNP as a requirement for multiplayer. Yet people can freely play the game without either, and inadvertently degrade the experience of those they connect with. It's been a problem since the Beta launch back in 2014, and unless something changes it will haunt ED well into Horizons...