We want more flexibility in working hours, but is flexibility a good thing? Most people cannot handle it very well.
Did you ever have a period when you were consistently behind in deadlines, where you never had a weekend, evening, or spring break free? Did you ever have a sabbatical where you ended up not getting things written? Did you have a period when you noticed that you weren't publishing as much.
It is likely that these period were both flexible and busy, but the time use was bad. It would have been better to have a less flexible attitude toward time. I was in the coffee shop in Saturday morning and sat at a large table with some women in the university who were timing themselves in 25 minute increments, then would take a nice break to talk to each other. If flexibility is so great, then why were they doing this? Because they understood that the key is not flexibility, but limits.