Expansion?

Check out the bias riddled throughout this BBC article, which is about how scientists have managed to link the genetics of people in the Middle East to those of the medieval Crusaders.

The BBC directly links the "Crusaders" to Christianity in paragraph 5. But it then mentions Islamic "expansions from the Arabian Peninsula which brought Islam to the area in the 7th and 8th Centuries." It mentions Muslim "expansion" four times in the article. But nowhere does it say HOW this expansion occurred: by jihad. But equate medieval Christians with the Crusaders? No such hesitancy. I wonder why that is?