Comment by adarsh_p

This may have been true during Darwin's time, but it simply does not apply in today'a academic world. The level of competition for grants, publications, etc. is way, way higher than before. Not that I've conducted a survey, but I'm pretty sure every professor at an R1 university works at least 60 hours a week, if not more.

Source: Am finishing up my PhD in theoretical high energy physics.