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”.
The MWOD approach still uses some techniques that look like classic stretching shapes, but with a strong focus on position and improving movement. The system also tends to look at improving other things before assuming an issue is a muscle length problem (as in the classic stretching paradigm).
Settle in, because there is no one episode for this question. It’s the basis of the entire MobilityWOD approach. Enjoy the trip.