Guild "challenges" (aka "being warred") happen for all sorts of reasons, and it's non-consensual like Borella said- there's nothing your officers could do.
People react to them in different ways.
Yes, it is forced PvP, but there are no consequences beyond inconvenience. You might die, but you res up with no death debt or dura loss.
Some people take a guild war very personally. I had a good friend that actually quit RoM over it, which surprised me, since it's a rare thing that does no long term harm to anyone.
My advice to you if your guild gets warred again is just to do one of these things:
- Suffer through it, or look for lowbees your size to pick on back. Chasing people your own size to fight with, and running away from the big scary people can actually be fun. They can't kill you if they can't find you, so hide and seek is a legitimate strategy.
- Work off some debt in the guild castle (assuming your guild castle is locked, and it should be!), rearrange the stuff in your bank inside your house, or hop inside an instance you can solo. If you're inside an instance or your house, they can't kill you, you're safe.
- Hop on an alt, or go take a walk. Most guild wars last between 30 mins and an hour. It'll be over before you know it.
Open-world pvp is actually kinda exhilarating if you're in the right frame of mind. It really is like a big game of hide and seek. You may even find yourself having fun- but there's no shame in just doing something else if you don't. Either way, don't let it get you down, guild wars don't last forever.