True, but asking this is an interesting way to spark a discussion. That's what I was doing-- stirring the pot. I agree that the Yang classics are mainly for the Yang and yang-derivative styles. But they did come form chen style, at least in part.
The styles differ but in some ways they are very similar. And martially speaking, their historical usage was a bit different from the common perception. consider this:
"In 1923 I began the study of Taijiquan from Chen Weiming in Shanghai. Master Chen and his own teacher, Yang Chengfu were just the same.
They loved to use ward-off and press to advance and attack."
http://www.nardis.com/~twchan/ph.html
Here we have evidence of the Yang family not practicing passive taiji push hands. different ffom the common perception.