I can understand, why this practice is frawned upon by some. If you see poker as a kind of sport, and the CC
freerolls as a way to practice as well as maybe connect with other forum members, then sit-out players definitely detract from the playing experience. But unfortunately there is no easy solution for this.
Even if CC made it a rule, that this is not allowed, there is no way for moderators to know, who are sitting out in the freerolls, other than members reporting each other. So enforcement would be very difficult and somewhat random. And of course its also not fair, if members would lose their freeroll access, just because something came up once or twice, and they forgot, they had registrered to the CC freeroll.
So my best advice to people, who are annoyed by this, is to play the CC freerolls on
pokerstars. On PokerStars a sit-out player always fold, even when they are forced all-in. So unlike other sites its not possible for the sit-out player to get lucky and win the forced all-in, after which they have chips enough for another orbit or two, and then maybe they win yet another forced all-in, etc.
On PokerStars it is next to impossible to cash without sitting in during at least part of the tournament, and that remove the incentive to register without intending to play. Of course there are still some sit-out players on PokerStars, but that is just part of the game and also happen in paid tournaments. People lose their internet connection, they fall asleep, or something comes up, so they have to go. This is nothing to get upset about. Instead we should just be happy for pick up the free chips, they are giving to us.