Soba is made of buckwheat so its really an very different type of dish, but Ramen used to be just called "Chinese Soba", since wheat based noodles are very different from rice or buckwheat.

Ramen specifically uses wheat noodles. "Modern Japanese Ramen" took Chinese recipes that used wheat noddles and used them to great effect during the American occupation with extremely cheap wheat prices (compared to other choice). You can be damn sure without cheap American wheat, Ramen would have stayed as Chinese Soba

It's one of those things that make people uncomfortable because history is messy.