No at all.
Typically, a police / fire department schedules X amount of officers / firemen for a particular day and shift. If a race requires a significant police and fire presence (Chicago, New York, Boston), you're obviously going to need a significant number of uniformed people to block roads, handle traffic, etc. If these officers are watching a bunch of runners, who is doing the normal police work (patrolling neighborhoods, responding to 911 calls, writing speeding tickets)?
Accordingly you'll have to bring in additional help to make certain that while every cop in the city is standing on the corner, some creep isn't breaking into your house. You obviously have to pay the additional cops, and the argument is the event should absorb this cost.
Seems reasonable to me.