One other common denominator of course might be the system. Pathfinder for example might be a favorite system but it is TERRIBLE for so many reasons on PbF.
I 100% agree with Heidi’s advice though. I am just about to try that strategy with my own PbF. I plan to pick through the PbF games I have played and request that the most enthusiastic players and colorful writers join my next game.
One other point is to give the story a middle and an end point. On PbF, it is easy to think the game will be going on forever and therefore to start thinking of your least favorite forum game you are in as a chore. Instead, I suggest running it more like a convention game, where you start hard framing scenes when the game becomes a grind or starts running way behind. For example, you might say, I want to get to the climax of this one-shot in 3 months.
For example, if you find you are still in the opening scene after a week of play (post-character creation), you might want to just re-frame the scene with the party on the road. Or, instead of allowing players to negotiate deals in town for 2 weeks, do an Apocalypse World style “love letter” and get them back into the adventure.
This certainly helps me because I know we won’t be lingering 3 weeks discussing why the players are going to go on a mission or negotiating a deal when they get to a random town. As soon as something like that happens in PbF, you will lose a player. If it happens a couple of times, you will lose everyone but the diehards.