Because I dislike the French...
Sorry, joking. For the same reason that we call 1, 2, 3 etc. Arabic numbers and not English numbers. We got them from the English, but the English got them from the Arabs.
Incidentally, I'm not sure the Arabs really did give us numbers:
You state, "its mathematicians created the algebra and algorithms that would enable the building of computers, and the creation of encryption." The fundamental basis of modern mathematics had been laid down not hundreds but thousands of years before by Assyrians and Babylonians, who already knew of the concept of zero, of the Pythagorean Theorem, and of many, many other developments expropriated by Arabs/Muslims (see History of Babylonian Mathematics, Neugebauer).