If it's not something that has any real effects, then it won't be used. The data you gather will probably not be very useful.
I should think that "lets your Ruler and General know, anonymously, that you consider the current situation boring" and "lets the dev team know that your leaders aren't doing enough to keep things interesting for you" should be enough to get at least a fair number of people to use it.
If this is something that gets implemented it will have to have some serious thought as to how to prevent abuse. Having a battle with another realm should result in a significant drop in the value. Possibly other things as well.
War can be as boring as peace, if it's the wrong war. March two weeks, fight one battle, march two weeks back to refit...or even replace the battle part with sitting staring across the border for five days because no one dares make the first move.
We need to know
what people actually find boring.
