I use private group for trade wings to grab the extra 5% trade bonus, I go solo in Res sites to bounty hunt and I go in Open for CZ action to take on other players (and generally get whupped). The game enables any person to play in the style they prefer.
What I find exciting is that this game is deserving of an award to recognise how it caters to the disabled, in that many add-ons are compatible (voice attack, track ir etc) and enable physically disabled players to experience the immersion experience.
You don't need a big budget to play this game. I use my business pc to play and it has the bog standard internal graphics that a few registry tweeks made the game playable and my trusty keyboard. I configured the keyboard to the old '84 keyboard layout specs and then added further key bindings, so that now, the entire qwerty keyboard is taken up with key bindings. I may not be as manoevrable as some with throttle, joystick, pedals etc, but I can still whizz around. It's ok for NPC but a lot more challenging against players.
So to summarise, I don't "do" open or solo or private group. I use them all, contingent on what I am doing in the game. All the (hundreds of pages of) posts about the merits of group, solo or open play miss the point to a degree and that is as a player, this game is versatile to cater to many different types of play and give the user a good experience. What I am urging is that for those who don't play open to give it a try and perhaps they will find a role, a niche where they may experience the "fun" that can be experienced in open play, while at the same time enjoying the "fun" from other types of play. Never say never, never say no, give it a try, give it a go.