Despite Mina commenting that the Student Council has more spine than the Japanese government, as she said already, they're naught but children in her eyes. She's in every way superior to them (except regarding their 3-sizes), and I think that actually comes into play more so than the dignity factor.

She cornered the Japanese government into a game they can't win more out of necessity. She lured the Student Council into a game they can't win more because it was fun. While having a match against a true rival can be exciting (depending on your person), watching someone struggle against overwhelming odds is also entertaining in its own right.

Nanami was smart, but she was in no way on any level to compete with Mina. It just so happens that the government is even one notch lower.

Two things that I'm growing to love about this anime are the nekomimi twin ribbons and the ED.