4. As good as Ubuntu's latest version and its UI may be right now, anything other than basic stuff you want to do requires command prompt. Normal users who are not geeks can't imagine themselves doing that on a daily basis.
Still wondering how they even go by doing their job on a computer. If you ever worked in a support role, you'd know that no matter how many years of experience they have, they are most likely being confused by the UI change every time MSFT decide to be 'cool' and 'innovate' (See the ribbon style introduction back in 2007). And this is without the regular nagging of them not wanting to learn where are the options they want to modify, despite the menus and sub menus.
With regards to MS Office and MS mail client, sure they are more polished, but does that really matter? Are those people crafting an art piece every time they want to add an image to their report? Just an honest question.