The big deal is that at least we'll all have a breather from the constant bickering between them. They'll have to find each other to continue with their spats.
The point isn't to ban them. We don't want to ban anybody that we don't have to. The point is to get their attention because their dispute is getting old.
But if it comes to banning, it takes the Moderators about 5 mouse clicks to make it happen. It takes considerably more time to register. Even the most determined individuals who re-register in order to continue to cause trouble get tired of it after awhile and go away.
I'll turn your question around to you. What's the big deal about simply being asked to stop acting juvenile? Seems simple enough. After all, I'm assuming they're adults. Capice?