There are several reasons why people who have a busy week at work may prefer using email over instant messaging for communication.

One main reason why diligent people with busy work weeks may prefer using email is that it is an asynchronous form of communication. This means that the sender and recipient do not have to be available at the same time in order to communicate. In contrast, instant messaging is a real-time form of communication that requires both parties to be online at the same time to exchange messages. For individuals with hectic work schedules, this can be a major benefit as it allows them to communicate with others at their own convenience, without the expectation of an immediate response.

Another reason why email may be preferred over instant messaging for individuals with a busy work schedule is that it allows for more thoughtful and considered communication. Since email is not a real-time medium, the recipient has the opportunity to take their time to carefully read and understand the message before crafting a response. This can be especially useful in situations where the recipient needs to consider multiple factors or consult with others before responding.

Finally, email also has the advantage of creating a written record of the communication, which can be useful for future reference. This can be especially important in a work setting, where clear and documented communication is often crucial.

Overall, while both email and instant messaging have their advantages, for individuals with a busy work schedule, the asynchronous nature of email and the ability to take more time to consider and respond to messages make it a preferred choice over instant messaging.