That is an interesting approach and you might actually be an outlier. However, in a generic context, the idea is that someone needs to take breaks to minimize the risk of exhaustion and other medical problems and it does make a difference in someone's overall productivity when they do not push themselves too much. So, to answer your original question "why would someone want to interrupt their workflow" the answer is: In general, even if someone loses a few of their valuable zoned-in epiphanies, they gain an overall well-being and retain their health, which makes them be productive all year-round.