It's not really the OS you use it's the applications. Until the application you need to use only runs on a Vista subsystem there is little reason to upgrade(a marketing word for change to a later version) your OS. Later versions are not necessarily superior and many people could still be using Windows 98 and Office 97 feature wise but the marketing machine makes you think that only chav scum use anything other than the latest versions.

I will have to use it because I have to support it, that's the only reason.