Yo, what Kelly means when he says “stretching is bad” is that the classic model for flexibility (hanging out at tissue end ranges with no real intent) is not a good solution to movement and mobility issues. He felt that the terms “stretching” and “flexibility” came with a lot of pre-conceived notions and misconceptions, so he decided to strike them from the MWOD vernacular in favor of “mobilty” and “mobilitizing”.