Get this woman out of Apple. She's in way over her head.
I'm not following how this is Ahrendt's fault? She doesn't control the production of the device; if there were issues that delayed manufacturing and left them with less stock to work with, she's taking the only really logical choice available to her. This also shouldn't really be a surprise to anyone who has been paying attention; she stated before that they would be selling the Watch online only for the time-being, she's just now formally acknowledging that they definitively won't be selling the Watch to walk-ins on the 24th.
Frankly, I think this is a refreshing new transparency for Apple when it comes to a product launch that you don't see very often.