What's in a name? Plenty, especially if you're rallying the democracy around your cause. Declaring a war on something is an American political tradition in that vein. I won't even get into how many Wars we have inside the US (on Drugs, on Poverty, on Homelessness, on High Prices...), can we have a war on "terror"? No, not really but that hasn't stopped the its mainstream use.
Finally, there seems to be traction to correct the misleading notion that we can have a Global War on Terror. Zbigniew Brzezinksi says why far better than I, he emphasizes the exercise of fear on the population.
While truth may actually require protection through a blanket of lies (the classic example being the deception around Operation Overlord), employing "war" when it's not appropriate isn't the same and will only lead to bad things, as Brzezinkski notes.
Other alternatives have their own problems. Replacing "terror" with "jihadism" would offend many Muslims, since jihad has positive, nonviolent connotations. "Jihadi-salafi," a term used by some scholars, is less offensive and more accurate but unlikely to play in Peoria. "Al-Qaeda" is logical, but experts now consider it more an inspiration than a mass organization. And al-Qaeda-ism doesn't exactly roll off the tongue.
Al-Qaeda isn't the only enemy and Salafism isn't the only ideology in opposition to the US. How about "War Against Child Killers And Militants Organized as Loose Entities"? It gives a nice acronym: WACK-A-MOLE.