Why isn't Sonnen vs Bisping happening on Fox?

I don't know if someone made a thread like this or not. The search here sucks, btw. Anyway, why doesn't the UFC have Bisping and Sonnen fight each other on the card instead of different opponents? This is a money fight which can lead into another money fight with Anderson. Bisping vs Silva will draw money or Sonnen/Silva 2 will draw money. Putting them against Munoz(Sonnen) and Maia(Bisping) could lead to disaster. Imagine if they both lose. Millions of potential viewers and money would be lost. If they can both fight on the same card, then make that fight instead. Bad business decision here, imo. What do you think?

Obviously...they don't wanna risk Bisping losing...
Why isn't it Bisping vs. Belcher, Kennedy, or the Ginger Ninja?
Because they don't wanna risk Bisping losing...
Who didn't see Bisping vs. Maia from a mile away?