This feature was implemented a few months and can be found in Options > Advanced > Interface, but it's disabled by default, so that newbies also know who is in each respective guild, etc

I don't see the need to have it on by default. Newbs have more to concentrate on that which guild is which or even what a guild is. By the time they know what guild they want to join, they have probably already installed a few plugins so an option like this is nothing to find and activate.

When installing a new client or just going to defaults I have to set many things under the interface tab to get the UI to my liking. I appreciate that you like this particular feature, but I have it off as what guild you are in makes no odds to me, so if I want it on it takes seconds to activate when changing my other preferred UI settings. I think the fact that the option is there is ace, but having is as a default option? Nah, best thing about being a newb is exploring.

Showing that the game has guilds active should be a good way to make noobs want to stay playing. Knowing they can team up and such.
+1