For an IT person it is much easier, why should I wait on hold to get a HDD or MB replaced under warranty. My time is valuable and when I need to spend an hour on the phone to get something like that done it is really a waste of time and energy.
Also when doing end user support a lot of times it is faster and easier when I can fire back an email with detailed instructions and screenshots on how to fix whatever issue it is. For those times when the problem is too complicated then you pick up the phone do a remote control session and resolve the issue. There is a fine balance between all of them.