I cannot answer the question at Tennessee, but the head coach or whoever called for the firing is doing that so they can keep the heat off of them.
Losing to Georgia in Athens is one thing. Losing to Kentucky at home is another.
BTW Tom Landry won 270 games and two out of five Super Bowls. He also had 20 straight winning seasons. He also is one of the quickest coaches to 50 losses. However, the owner gave him an extension during the losing seasons. Then again it was tougher for expansion teams during those days. However, that was then, and this is now.