Squat depth

Just wondering if you guys have ever had anyone so inflexible that they could not even achieve the squat stretch position as described in Starting Strength (not including old age, obesity, stance width and foot position etc). If you did, what did you do to rectify it? I know Rip has stated that such people don’t exist, thought you guys might have a different take though. Thanks for your time.

We have them keep training, and they get there.