With the greatest respect, we've spent 20 years trying to get pilots to not say 'it would never happen in my airline'!
I believe WE are all capable of having that disastrous day at the office given enough rope and bad luck. The question we should be asking is not why then but how did we make sure it's not us!
I can 100% understand how the combination of SFO approach control, a lack of GS, and a pilot converting from an Airbus to a Boeing could lead to a slow speed event. I'd hope the training regime and cockpit gradients in my airline would mean that even working at the mitigate level would avoid a crash but I think it's a dangerous mindset to think it 'couldn't happen.