"Microsoft gave us a 98% discount..."
While this is undoubtedly true (at least it is in my own experience with the NHS). I also think that the "if it ain’t broke, don't fix it" approach to maintenance is partly responsible as well. I can't fault someone for taking this pragmatic approach to IT systems, but it does mean that once a vendor gets in, it's really hard to get them out even if the competition is cheaper, better and faster Etc.
I believe that many companies or government departments could run on open source software if will to do so exists within management. However, It's always easier for jobs-worth staff to maintain the status quo even if doing so is detrimental to the budget.
The idea that it is cheaper to pay for windows and office as opposed to using open source alternatives is incorrect in my own experience. I know that MS advocates like to talk about total cost of ownership and the cost of retraining staff, the price of a UNIX admin vs the price of a Windows admin etc however in my own experience, the average government employee is woefully under-trained with their current windows system never mind a new one and you don't need as many UNIX admins as you do windows ones because a well configured UNIX environment is far more smooth running.
One of the most significant cost differences presented in TCO analysis is the bespoke software that will need to be re-written to run on the open source OS. The reality is that these systems are still running on a dusty COM+, Windows 2000 and SQL 2000 cluster in the rack. What the non-technical management bods don't get from the TCO analysis is that this lot will all need re-writing for the next version of Windows anyway.
It is incorrect and disingenuous to suggest that change needs to be all-or-nothing or that the cost of change needs to all be paid in advance, reality is that many versions of many operating systems are already running in Mr Creese's organisation, he's probably got more than one version of MS office installed in his organization as well. At the very least he will have migrated from old versions of office to newer ones in the past and frankly if he's moved staff from any previous version of office to any version of office after they changed to use the ribbon menu he's already had and paid for the level of change and retraining he could expect to migrate from MS office to LibreOffice.
It's good management to minimize unnecessary cost and protect your organisation from over-exposure or reliance on any one vendor, this is especially true when you are running a government department. What is Mr Creese doing to manage this risk of over-reliance on Microsoft?