In a busy workday, chances are that you already have plenty of disturbance, there is no need for every to be another.
Often, as the first ting in the morning, we want to get to our calendar to start planning the day.
Outlook by default opens your email, and it becomes overly hard to ignore all that pending email. Well instead of having to rely on willpower, you can instead just change the default tab to "Calendar":
Computers are supposed to be helping us, not stressing us out.