Well.....sure, a lot more people die from diseases than acts of terrorism, but we might actually prevent the latter. We've been working on cures for the former for a long time, and shunting money away from anti-terrorism efforts might not make any significant impact on our progress toward disease cures.
The obvious counter-argument would be,"Yeah, and what has the billions spent on anti-terrorism measures gotten us, aside from a huge up-jump in federal dead wood (Homeland Security playing I-Spy and generating mountains of classified BS at the expense of the taxpayer,) longer waits at the airport (enough said,) and distraction from non-terrorist threats (e.g. acts of nature, pollution, and diseases)?"
Zipping back to the other side of the court, the requisite counter-argument to that: "Preventative action doesn't yield glamorous results, but that doesn't make them irrelevant or valueless. We can't ignore the folks who are trying to kill us. And we shouldn't focus solely on blocking their short-term attempts. We need to secure the future for our children and fight our enemies."
....Good Lord, I'm talking to myself on an internet forum. This can't be a good sign.