Speaking just my personal opinion now..
I think there are a couple of problems with completely pacificist guild. The first one is that has no role to play at all. Protecting trees or something like that will end up becoming very passive. There's just no idea behind it. Unless you have some sort of other guild who actually very much needs the trees. Or if the trees are somehow central to the theme of the game. I mean it's a nice fluffy idea to protect some trees, but it just becomes irrelevant otherwise. We do not want stuff that doesn't connect to anything.
On a more general note regarding guilds, I think we have two groups:
1) There is a big group of cross-guild, cross-race, cross-culture players who are all good friends. This obviously creates absolutely no game content except for perhaps rubbing the ego of the super-friendliest characters. In essence, it creates self-sufficiency which in turn kills the need for interaction between players.
2) The cliques of players that aren't often ends up sidelined and irrelevant. This usually ends up in pointless PVP without any story at all to it (e.g. think kill-on-sight/psychopath "RP") which is just as bad. It might all be interesting, but then all of this just as possible without the guild.
The guilds have a certain lack of purpose, and in the case were it's been tried to add one it I think it didn't work too well. Sometimes because it was interpreted differently than intended and sometimes because it just wasn't that great to begin with.
We need to think what guilds are for in the first place. But it is for certain that we do not want everyone to be best-friends (or auto-kill for that matter). Nor do we want them to be an "armour/weapon set". Furthermore, they should not be passive (e.g. defending some useless asset). They need an active goal they can pursue in their day-to-day, one that matters/make sense and truly affect other characters (in a non-cosmetical way). In essence they should drive interaction and RP. Nobody should remain unaffected, self-sufficient and all-powerful. Sadly, this is untrue for nearly every guild in the game at the current time (I'd like to think of the Crusaders as the only guild with a really clear-cut goal that makes sense - however they alone are a bit narrow). It's hard to fix. Especially with picky customers
I'd also like to add that it's a common mis-conception that Evren is somehow angered if someone e.g. cuts down a single tree (I'm quite sure Abharsair wrote about this on the wiki before) or that they are somehow peacelovers (not sure if somebody thought this, but I might just clarify that just in case). I also believe that the miracles will always stay stronger than any magic that is ever introduced into the game, simply because that's the way we want it.