Definitely worse than a real Champion who doesn't defend his real belt is a Interim Champion that doesn't defend his interim belt.
In a time span of 7 months, Renan Barao defended his interim belt two times after earning it in July 2012. That's a pretty active interim Champion and always blessing us with mind blowing performances.
I totally agree. Renan Barao is the man. Unfortunately the UFC isn't blessed with many fighters with his outlook.