Perhaps I should clarify: when I say that adopting flex time requires a leap of faith for certain companies, I'm simply making an observation. I don't condone that mindset. In fact, I think it's every bit as ridiculous and antiquated as you do. But a lot of employers are old-school that way: they don't trust their employees, and opening up to a concept like flex time is inherently going to require a bit of a leap of faith for them.
My entire point was that such companies -- as it so happens, a lot of companies -- still view their employees from an inherent place of mistrust or wariness. Yes, it's their problem. And yes, it will prevent them from getting the best and brightest. No argument there. I was simply pointing out that such a mindset exists and that it is still fairly prevalent. I was not in any way justifying it or lending credence to it.
In a perfect world, I agree: it should not have to be a leap of faith. But in the world as it exists, it's still a big jump for many, many employers.