Why are rings unique equipped?

[Myric]

I see people do this a lot and I've always wondered if the secondaries on the "off" ring outweigh losing so much of your primary stat.

It isn't even close to worth it and the people that do it are gimping their dps or healing, though not by a lot. The only role it doesn't effect is tanks. Getting a Str ring is pretty much as good as the Vit ring.