Agree in part and disagree in part. People may well be upset that their taxes don't provide instant service in response to any contingency. Your suggestion will leave them thinking that it would be possible to provide instant service if only the budget were bigger/taxes were higher/the economy was better, etc. They are still going to be angry.

It might be better to preempt that whole line of reasoning, with something like:

"No emergency service agency, regardless of size or budget, can plan and prepare to instantly respond to every possible disaster or large-scale emergency. We will provide the quickest and most professional response humanly possible . . . . . "

That's just off the top of my head. Martin can probably word it better, but hopefully you understand what I am getting at.