That wasn’t really the issue. The problem at the time was the Big 12’s then-revenue-sharing-structure.
Rather than equally splitting everything among all the teams (like the SEC, Big 10, and ACC did), the Big 12 had an unequal revenue sharing set up that was kind of weird (it was a sort of odd set up; that year’s performances in sports weighed heavily in determining the amounts but somehow it also factored together in a way to essentially keep the conference’s biggest brands on or near the top…their system was lucrative enough to those bigger brand teams that Texas, Texas A&M, Nebraska, and Oklahoma all voted against equal revenue distribution in 2008).
The set up left Colorado consistently in the bottom half receiving conference revenue: when they moved they went from receiving the 7th ($9.7M) and 10th ($8M) in the conference’s shared revenue each year to receiving $19M, $21M, $25M, and $28M in yearly shared revenue
Nebraska’s move, though, was entirely about getting more money. Moving to the Big 10 took them from receiving only around $9M a year from their conference to receiving $22M, $29M, $33M, and $48M in yearly conference shared revenue.