Here's the deal. As a non-nexus guy I didn't want to attack (or avoid) Nexus unless I had to. If I knew a Nexus guy would tell me the balance had changed, then I could treat him as a "friendly" until such time as he informed me he wasn't. If I didn't think he was the type to inform me, then I had to treat him as a constant enemy, because at any given time he could be trying to kill me.

If I had been evil, then, and a nexus character refused to give me a heads up when the balance changed, then I'm going to treat that guy as a permanent enemy and (unlike a goodie) I'm going to hunt him down and kill him whenever I had the opportunity. Were I to do this, he'd probably be like, "But I'm your friend right now! Light tips!"

Thing is, that amounts to him only telling me what the balance is when it benefits him. Basically "I'm going to keep you in the dark about the balance when it allows me to gain the element of surprise, but if you start coming after me when light tips, I'm going to tell you light tips in order to get you off my back."

To me, as the non-nexus guy, that's not acceptable. If you're not willing to give me a heads up then you're on the perma-enemy list. If I'm good-aligned then maybe I just avoid you at all times and assume you're out to kill me. If I'm evil then maybe I hunt you down and kill you, regardless of where the balance sits, every time I see you.