If you are a highly organized people, (almost OCD), you could have some success taking science as a 9-to-5 job. It is not the case of most people. Science is an all-consuming profession and it is more than a job. I am not advocating that it has to consume your life, but it is different than have ordinary job. Sometimes you need to be alone, sometimes you need to talk people. You have to be free to think and work in whatever way you find best, but you can not hold back and say "Hum.. 5 PM! See you tomorrow cell culture! See you tomorrow deadline! See you tomorrow incredible new idea. I think 10 hours/day is the real thing for many scientists (early and late career).
There are two kinds of 9-to-5 scientists: (1) those with great organizational skills in the workplace and (2) those that hide themselves behind the work-life balance speech, but are just lazy. The rest of us have to deal with the raw and wild academia. This is my personal opinion, I totally respect different points of views and other experiences.