I think for me it's because capitalism can manifest in a variety of ways - there are examples of it back into the Middle Ages, when we were mostly still getting conquered vs. doing the conquering (so much. Crusades and the general inbreeding of most of Europe's monarchies makes this a Very Complicated Topic that I haven't done reading on in a long while). Capitalism definitely propagates through imperialism, but it's capable of doing so in different ways as well.
Of course you are, you nice little informant
(you're the one who came out with the bizarre nonsense of being apolitical in a genocidal police state, not me)