People talk all this doom and gloom like new people aren't joining the game every day (that aren't bots!) to replace the fairweathers who go traipsing off to go do whatever and never return. But guess what... they are! It's when influx no longer keeps up with outflow that there is a problem. This game has not yet reached that point.

(On another note, my FC doesn't retain inactive players beyond a certain point without an explanation as to their absence. Be active, or be gone; there's no point in carrying hundreds of members' dead weight. If they come back and liked their experience with us, they can rejoin. If not, they can always find another FC.)