why tasks assigned to another person show up on their calenders?

why tasks assigned to another person show up on their calenders?

I am assigning tasks to other persons, both from my personal and groups, and the tasks do not show up in the persons calender view, why not?  should a date specific task, which all are, show up on either the personal calender of the person it is assigned to, or if it was assigned under a group, in the assigned persons calender view for that group?