On one hand, the lack of clear policies and regulations governing academia is one of its greatest advantages, because it gives your mind space to explore, and expands creative freedom. If you want to work from 5pm - 3am, nobody will stop you. Ultimately you work for your own advancement, set your own goals, and plan your own schedule.
On the other hand, when other people are involved, especially those with "seniority" like P.I.'s and advisors, it's no longer obvious what decisions you should make. You need to consider more than just yourself, but the lack of regulation creates ambiguity in the "politics" of academia. How do you balance the expectations of those with some power over you, with the expectations you have of yourself? I imagine this question is a source of pressure for many academics, especially those who are extrinsically motivated.