I don't know about UC, but it's my understanding that in many universities, the football programs pay for themselves and then some.
As for the investment officers, someone has to manage the universities' endowments. Certainly, they could just liquidate their endowments and spend it immediately on, say, urgent needs and tuition reduction. But then when they need to, e.g., renovate a dorm, they will lack the money to do so.
At any decent team this is the case (that football pays for itself, plus the other sports programs). Shit even at my alma mater which was awful (at football), this was still the case, and the head coach brought in like $1m/yr. Lot of money there.
Not enough to pay for that fancy new stadium though...
As for the investment officers, someone has to manage the universities' endowments. Certainly, they could just liquidate their endowments and spend it immediately on, say, urgent needs and tuition reduction. But then when they need to, e.g., renovate a dorm, they will lack the money to do so.