Not a fan of this idea at all.
There are a huge number of problems with it, particularly if it applied negative impacts on governments, rulers or realms.
So we give players a button to say they find their realm boring. Who's to say that isn't partially their own fault? You can't lay everything on the rulers. It's an invitation for players to say, "I'm bored,
you do something to make it interesting for me". Rather than, "I'm bored, what can I do to make this realm more interesting for us all?". Fair enough, being a ruler places a greater responsibility on a player to try to make things entertaining, but things are often beyond the control of one player to change.
Which brings me to the second point. Players in realm A press the 'Boring, boring, boring' button. So the ruler does what s/he can to start a war. The rulers of their allies in realms B and C take a look at what their own players are saying and find they are content with the
status quo. Realm A is forced into a suicidal war without allied support.
Heck, we could start with it having no IG effect at all beyond information—let the ruler and general know, and send the information to the dev team, as well, so we can get an overview of which realms are considered significantly boring.
If we see that some realms have a high percentage of players who think they're boring, then we can implement some kind of relatively slow-ramping negative effects.
I really don't think siccing the Dev team on a realm would be a good idea. Isn't that the sort of intervention that's always been avoided? Also, would players really be so foolish as to do something that would bring down negative effects on the realm they're playing in? Rather than... you know... talking to the leadership, stirring up internal dissent, or just leaving to find a realm they consider more interesting?
And that's really what it boils down to. If players find the realm boring and are dissatisfied we already have a mechanism to address that - pack your bags and move somewhere else. The only reason for them to stay in the realm and also say it's boring is so they can keep a title or some other perk while blaming someone else.
Sorry if that comes across as a harsh criticism, but it reflects how much I dislike this idea.