Sure. What's universal is universal. But what's the point of defining something as capitalist (or anything) if it applies to every case.
Characteristics of capitalism (let's go with the Marxist definition) certainly aren't universal. Not every human economy includes private property, for example. Not every system include a bourgiouse elite, a customary, religious or military elite is more common historicaly.
I wasn't referring to specific theories. My point was more about observing how the world is.