"SFO atc has been the first part of my Threat brief for some time, ive felt there's been an accident waiting to happen there for some time, if there's a cultural problem here it's not all in seoul!" (Where is the "Quote" button on this forum?)
I've been waiting to see if this was mentioned, as it was starting to play on my mind. There is an unfortunate aspect to dealing with some officials in the USA, which is that they regard those they are meant to be working for as a nuisance, and anyone asking for more than is offered is made to feel that they are ... well, let's say "unappreciated"
This is cultural, and I doubt that SFO ATC are any less prone to it than any other "public servant" in the country. However, it is an attitude that will put people off asking for assistance/clarification/reassurance. I suspect that CRM might be needed in more places than Asiana.