re: Was there this much honest resentment about A&M and Mizzou?

You’d have to understand the bad blood between the 2 and how long that’s been festering. Plus Texas is exactly what many are warning about. They are a cancer. They may initially appear to toe the line and play nice but long term it’s just not in their genetic makeup.
They’re the most dysfunctional program there is because of the politics they play and the selfishness they exude.