[joey_spaztard]

I think that part of it is central management, specifically Microsoft Active Directory.

The whole thing of pushing out software, software updates, central control of user accounts and password resets, logging and more.

"Joe Bloggs is fired, turn off his account on every computer"

"The marketing VP wants this new logo on every desktop background today"

"Security breach! make everyone change their passwords!"

Central management for linux boxes is nowhere near as "point and click".

[josephcsible]

But Linux does support those things. Changes like deploying software and desktop background changes are easy with configuration management systems like Puppet, and centralized user account control exists with SSSD (and it even connects to AD if you have it, so you can use the same accounts on Windows and Linux).