I'm curious who these PG/solo vs PG/solo "cohort"s are. I've never seen the PG/solo contingent described in quite that way. My experience is that the PG/solo powerplay crowd are a subset of Empire/Grom players (who also don't hide or deny the fact), and then 5Cers.
Quite simply, there's always been a cohort of players who play games simply to ruin the experience of others, and they'll take the path of least resistence to do so. In games with open-PvP, they'll be drawn to player-killing newbies and PvE oriented players, and then combat log at the merest hint anyone who can defend themselves. In pure PvE games, they'll kill steal, block access to NPCs, trigger mob rushes, or other disruptive behaviors. In PvE games where there's "dual requests," they'll spam said requests so that you'll get killed by the mobs. In games with ELO ratings, they'll deliberately trash their rating so that they'll get matched with inexperienced players.
In Elite: Dangerous, this cohort can't
easily mess with others in Open. Open is too difficult, and frequently too dangerous, to do player-killing consequence free. And because Open
is an open-PvP environment, it's
also problematic for them to use indirect ways of messing with others while in Open. So they move to solo instead. 5C is a classic example of this type of behavior.
Of course, these aren't the
only types of players who aren't fun to play with. Some players simply don't realize that they're having a negative effect on others with their behavior. Thankfully, many of
those players will
also be naturally drawn to Solo/PG as well when given the option.
This has resulted in an Open population where the amount unfun behavior is
much lower compared to similar games I've played in the past. As a result, and much to my surprise, I have fun in Open. Part of that is, without a doubt, the crummy instancing. But mostly, it's because the types of players I least want to play with are walled away in Solo/PG, where they're the
least effective and ruining my gameplay, and frequently they're so ineffective at doing so, I don't even notice that they even
exist.