Naming conventions can seem a bit weird. For example, here in the States we know the Seven Years' War (well, to the extent that we know it at all) as the French and Indian War because... it was fought between the French and... the English, with various Native American tribes joining in on the French side. Southern sympathizers liked to call the American Civil War the War of Northern Aggression. I'd imagine that the English don't really care to call the Revolutionary War by the same name (or perhaps even refer to it as a war).
If anything, I'd say the Spanish-American War is more descriptive than a lot of those names. The US did, in the end, fight against the Spanish, even if they did so primarily in Cuba, and the spoils of that conflict certainly indicate that the USA was up against all of Spain - they took home not just Cuba but also the Philippines, Guam, and Puerto Rico. In fact, there were even a couple of (relatively minor) pitched battles in the Pacific Ocean:
For that matter, Puerto Rico saw some action:
I'm sorry, but this was flat-out not just a war (however short) about only Cuba. It was the United States' first real foray into imperialism (setting aside the "Manifest Destiny" expansion across the North American continent).