Key users hated Linux and their know-it-all IT administration prescribing them software that nobody else uses. During the time the IT department failed to provide a solution that was better than the MS offering. The user interface is different and the compatibility lacked badly.

Let's be honest. How do you beat MS Office using Linux solutions? Will your Excel documents with macros still work flawlessly? How would you replace Exchange? Maybe Thunderbird with what calendar solution? There are tons of material and training for everyday MS Office use and most people are already familiar with the details they need. For OpenOffice... not as much... OpenOffice isn't even really developed anymore as people switch to LibreOffice.