The CTO doesn't know enough to drive technology decisions from the top down, and has instituted a culture too afraid to make suggestions from the bottom up.
Redundancies are viewed as waste. Overprovisioning for large events seen as a "failure to build to scale the first time".
You can't say in a meeting that you think the cache is a single point of failure because the bozo at the top might say something idiotic like "failure is not an option!" and fire you.