My guess is the answer is "no, it doesn't scare many off".

I didn't know about the Facebook open-plan office, but I just went through the interview process for a similarly well known company, and everything saw at the interviews and on videos of their offices was the opposite of good.

But it never occurred to me to shy away from the job because of that.

I am sure they know these offices are bad for productivity, but for some reason they like to buy expensive real-estate, the inefficiency is paid for by the savings on rent.