Exactly. The Office file formats are still extremely ubiquitous in the business world, and if you use something like LibreOffice to modify them, the formatting of the documents is almost guaranteed to go crazy, without you possibly not even knowing it, and ultimately losing customers. I'm sorry, but it has just been incredibly practical decision to just install the fucking Microsoft Office. Of course this UK Cabinet's decision is another step towards open standards, so I guess that's good.
Outside of bookmarks in Writer I find OpenOffice/LibreOffice to generate more compliant documents to Microsoft's tools than Microsoft's tools do. They're also typically smaller even when saved in the Microsoft formats.