I would go by the respective use of the room. We also have higher windows in the bathroom, and in hindsight, I would do it differently. What other reason is there for this, aside from the exterior view, although we would not like the house any less if there were deeper windows in that spot? I once asked my buddy these questions, and he dryly replied: Do you often sit in the garden and look at the position of the windows? Question answered! Allegedly, it is the case that architects tend to pay more attention to the exterior view (after all, it is their publicly visible design) and interior designers focus more on "the interior/function." Aha... that must be where the job title comes from :D. Unless there is a real, specific use for such a window in the room, I would not set the parapet so high.