English is the primary programming language, not because a team of dedicated Anglo-Saxons are pointing rifles as the head of brown people, but because American trade provides the most profit motive between 1974-2008.
A "primary methodology" only applies in "most" cases, not all of them.
Lots of languages have perished for outside forces other than trade -- the Hebrew wasn't abandoned because a better trade language came around, but because Israel was conquered and the locals scattered. Other languages were persecuted by decree. Others died because their native speakers were eliminated. And several other ways (e.g. Mussolini tried to smooth out local dialects of italian using the powers of government plus radio and early cinema).
Religion can and does preserve memes and linguistics, but only trade can scale it out.
If it was just for trade, language learning would be relegated to merchants in those countries and few others.
Government, bureaucracy and occupation matters more than trade in this regard. That's how latin become the norm in a large area during the roman empire -- and not because everybody in those regions traded directly with Romans or couldn't agree on pricing otherwise.
Same e.g. for French -- it's not because of trade they got big as a language in the 18-early 20th centuries, but because the french run a big colonial empire.
And English, beyond trade, were the language of the big British colonial empire, and afterwards of the dominant culturally power that was America (Hollywood, rock, pop culture etc.).