IEDs and Homeland Security Dollars

The US leadership was criticized (rightly) for planning the Iraq adventure without thinking realistically about the likely threats. I'm not sure why DHS-types in Massachusetts wouldn't think that the deadliest weapon used by terrorists in Iraq and Afghanistan might be used against Americans here in the US. Generals always (initially at least) fight the last war, and I can't believe AQ and its ilk are any different. IEDs have worked especially well in Iraq. Perhaps though, its not that the IEDs have worked well, its just that every other tactic has worked so poorly.
AQ has found that standing up to the Americans in pitched battles and firefights is nothing less than suicide without any hope of real results. A good bomb maker can assemble hundreds of IEDs which can be planted by any old goon. That is a better return on the investment. So IEDs are the weapon of choice used by terrorists in Iraq and Afghanistan. Why on earth wouldn't anyone believe that small-scale terrorist attacks in America would vary much from this formula? Low-risk, low-cost, variable-reward sure beats out high-risk, high-cost, low-reward any time.
The likelihood of terrorist attacks, especially small-scale attacks are a question for another debate. Take it as given that both the federal and state governments consider it a realistic possibility. Shouldn't the states use the grant money they get to prepare for the most likely form of attack? Buying equipment which can be used to support counter-terrorism in many ways is just wise use of resources, but using Homeland Security money to buy trucks to pull horses around is another (last paragraph of the linked NYT article).