As a newbie to this game, but long time mmog player, I thought I'd give my 2 dappers on the subject.
First of all my background so you know where I'm coming from. I'm 25 years old and have been playing online games with guilds/clans/whatever for 8 of those. During that time I've only had four games I've been seriously involved in, playing for more than a few months. Three of them I played for over two years, so when I find a game I really like, I stick to it.
In those three games I was in one or two guilds each the time I played. The guilds all fluctuated wildly in members during the time I played, ranging from about 5-6 members to over 60 in the most extreme case (fluctuation-wise). Members left other guilds for us, and vice versa. We had periods of agressive recruiting, both from other guilds and newbies; and got members 'stolen' in return now and then.
To me this is just the ebb and flow of a guilds life. It is always up to the players themselves if they want to join or leave a guild. If they are happy in the guild they will just be annoyed if another guild comes after them with bribes or whatever to join them instead. If they are unhappy they would have left anyway in time, and up to the point they gather the courage to quit by themselves they will most likely not enjoy the game much. In this case the recruiting attempt on an already guilded player is a good thing. Everyone is allowed to leave a guild if they want to, and there's nothing wrong with them getting help, right?
I voted for "All is fair..." since if a guild gets too aggressive in their recruiting attempts they will quickly get a bad reputation in the community. In most cases this will lead to that guild getting a very hard time finding new members, and at least some of their own members leaving. Online game communities are generally really good at this kind of self-regulation.
Now for a slightly off-topic, but related subject.
I can't even remember how many games I've tried out for a week or two to find the next 'big game' for me and possibly a few friends who's played with me in the past. And I've come in contact with the 'zergling' recruiting countless times.
As a newbie in any mmog I count on being offered to join a guild for the first time within two-three days. It hasn't failed yet, not in this game either. Sometimes this comes from a fellow newbie in the game with grand plans or a small budding guild of new-ish players, but mostly it's a big guild who wants to get even bigger.
Personally I find it a bit annoying to be approached this way before I've even decided if my first impression of the game is favourable enough for me to take the time to learn it. A guild to me is a big commitment, even if I wouldn't hesitate long before leaving a guild I didn't like. But having to deal with that kind of thing before I even know if I like the game itself or not would definately be a big minus when the trial is over and it's time to decide if I want to keep playing.
Fortunately I doubt many of the guilds who are recruiting among the less then a week old players will treat those players bad or ignore them once they're settled in the guild. But there's always some bad seeds, and any new player who has the misfortune of joining such a guild in their first few days in the game will most likely not play it for very long. Without happy new players a game will die a slow painful death as the established players start to leave for other things.
So to any guild recruiting new players: Please take good care of them.
My character is a Matis named Idgar, currently on his way to become a knight. Feel free to chat with me ingame if you like, I enjoy a good chat if I'm not too busy. But no guild invites yet, please. If I'm still around next weekend (not the coming one) however, it means I'm subscribing and should be considered fair game.
((Wow, I just can't stop typing sometimes. I didn't mean to write this much.
))