When I say casual players I do not mean f2p but I believe there is a significant portion of subs who are casual players, not doing end game content (ops or hm fps) leveling alts and mostly playing the game as a single player game. you guys I think underestimate the barrier of entering into an ops group even with a guild support. I know a lot of people in my guild don't do any ops or hard mode fps.
Ah yes, I misunderstood you. Sorry.
I don't have a good sense for how many people avoid anything other than the solo leveling content. I'd like to believe that the SM ops are approachable enough that anyone with any interest in them at all would join one of the dozens of pug groups that form each night.